/*
  * copyright (c) 2001 Fabrice Bellard
  *

  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

  * version 2.1 of the License, or (at your option) any later version.

  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */
 

 #ifndef AVCODEC_AVCODEC_H
 #define AVCODEC_AVCODEC_H

 /**

  * @file

  * external API header

  */
 

 #include <errno.h>

 #include "libavutil/samplefmt.h"

 #include "libavutil/avutil.h"

 #include "libavutil/cpu.h"

 #include "libavutil/channel_layout.h"

 #include "libavutil/dict.h"

 #include "libavutil/log.h"

 #include "libavutil/pixfmt.h"

 #include "libavutil/rational.h"

 #include "libavcodec/version.h"

 /**
  * @defgroup libavc Encoding/Decoding Library
  * @{
  *
  * @defgroup lavc_decoding Decoding
  * @{
  * @}
  *
  * @defgroup lavc_encoding Encoding
  * @{
  * @}
  *
  * @defgroup lavc_codec Codecs
  * @{
  * @defgroup lavc_codec_native Native Codecs
  * @{
  * @}
  * @defgroup lavc_codec_wrappers External library wrappers
  * @{
  * @}
  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
  * @{
  * @}
  * @}
  * @defgroup lavc_internal Internal
  * @{
  * @}
  * @}
  *
  */
 

 /**
  * @defgroup lavc_core Core functions/structures.
  * @ingroup libavc
  *
  * Basic definitions, functions for querying libavcodec capabilities,
  * allocating core structures, etc.
  * @{
  */

 /**

  * Identify the syntax and semantics of the bitstream.

  * The principle is roughly:
  * Two decoders with the same ID can decode the same streams.
  * Two encoders with the same ID can encode compatible streams.
  * There may be slight deviations from the principle due to implementation
  * details.

  *

  * If you add a codec ID to this list, add it so that
  * 1. no value of a existing codec ID changes (that would break ABI),

  * 2. Give it a value which when taken as ASCII is recognized uniquely by a human as this specific codec.

  *    This ensures that 2 forks can independently add AVCodecIDs without producing conflicts.

  *
  * After adding new codec IDs, do not forget to add an entry to the codec
  * descriptor list and bump libavcodec minor version.

  */

 enum AVCodecID {
     AV_CODEC_ID_NONE,

 
     /* video codecs */

     AV_CODEC_ID_MPEG1VIDEO,
     AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
     AV_CODEC_ID_MPEG2VIDEO_XVMC,
     AV_CODEC_ID_H261,
     AV_CODEC_ID_H263,
     AV_CODEC_ID_RV10,
     AV_CODEC_ID_RV20,
     AV_CODEC_ID_MJPEG,
     AV_CODEC_ID_MJPEGB,
     AV_CODEC_ID_LJPEG,
     AV_CODEC_ID_SP5X,
     AV_CODEC_ID_JPEGLS,
     AV_CODEC_ID_MPEG4,
     AV_CODEC_ID_RAWVIDEO,
     AV_CODEC_ID_MSMPEG4V1,
     AV_CODEC_ID_MSMPEG4V2,
     AV_CODEC_ID_MSMPEG4V3,
     AV_CODEC_ID_WMV1,
     AV_CODEC_ID_WMV2,
     AV_CODEC_ID_H263P,
     AV_CODEC_ID_H263I,
     AV_CODEC_ID_FLV1,
     AV_CODEC_ID_SVQ1,
     AV_CODEC_ID_SVQ3,
     AV_CODEC_ID_DVVIDEO,
     AV_CODEC_ID_HUFFYUV,
     AV_CODEC_ID_CYUV,
     AV_CODEC_ID_H264,
     AV_CODEC_ID_INDEO3,
     AV_CODEC_ID_VP3,
     AV_CODEC_ID_THEORA,
     AV_CODEC_ID_ASV1,
     AV_CODEC_ID_ASV2,
     AV_CODEC_ID_FFV1,
     AV_CODEC_ID_4XM,
     AV_CODEC_ID_VCR1,
     AV_CODEC_ID_CLJR,
     AV_CODEC_ID_MDEC,
     AV_CODEC_ID_ROQ,
     AV_CODEC_ID_INTERPLAY_VIDEO,
     AV_CODEC_ID_XAN_WC3,
     AV_CODEC_ID_XAN_WC4,
     AV_CODEC_ID_RPZA,
     AV_CODEC_ID_CINEPAK,
     AV_CODEC_ID_WS_VQA,
     AV_CODEC_ID_MSRLE,
     AV_CODEC_ID_MSVIDEO1,
     AV_CODEC_ID_IDCIN,
     AV_CODEC_ID_8BPS,
     AV_CODEC_ID_SMC,
     AV_CODEC_ID_FLIC,
     AV_CODEC_ID_TRUEMOTION1,
     AV_CODEC_ID_VMDVIDEO,
     AV_CODEC_ID_MSZH,
     AV_CODEC_ID_ZLIB,
     AV_CODEC_ID_QTRLE,
     AV_CODEC_ID_SNOW,
     AV_CODEC_ID_TSCC,
     AV_CODEC_ID_ULTI,
     AV_CODEC_ID_QDRAW,
     AV_CODEC_ID_VIXL,
     AV_CODEC_ID_QPEG,
     AV_CODEC_ID_PNG,
     AV_CODEC_ID_PPM,
     AV_CODEC_ID_PBM,
     AV_CODEC_ID_PGM,
     AV_CODEC_ID_PGMYUV,
     AV_CODEC_ID_PAM,
     AV_CODEC_ID_FFVHUFF,
     AV_CODEC_ID_RV30,
     AV_CODEC_ID_RV40,
     AV_CODEC_ID_VC1,
     AV_CODEC_ID_WMV3,
     AV_CODEC_ID_LOCO,
     AV_CODEC_ID_WNV1,
     AV_CODEC_ID_AASC,
     AV_CODEC_ID_INDEO2,
     AV_CODEC_ID_FRAPS,
     AV_CODEC_ID_TRUEMOTION2,
     AV_CODEC_ID_BMP,
     AV_CODEC_ID_CSCD,
     AV_CODEC_ID_MMVIDEO,
     AV_CODEC_ID_ZMBV,
     AV_CODEC_ID_AVS,
     AV_CODEC_ID_SMACKVIDEO,
     AV_CODEC_ID_NUV,
     AV_CODEC_ID_KMVC,
     AV_CODEC_ID_FLASHSV,
     AV_CODEC_ID_CAVS,
     AV_CODEC_ID_JPEG2000,
     AV_CODEC_ID_VMNC,
     AV_CODEC_ID_VP5,
     AV_CODEC_ID_VP6,
     AV_CODEC_ID_VP6F,
     AV_CODEC_ID_TARGA,
     AV_CODEC_ID_DSICINVIDEO,
     AV_CODEC_ID_TIERTEXSEQVIDEO,
     AV_CODEC_ID_TIFF,
     AV_CODEC_ID_GIF,
     AV_CODEC_ID_DXA,
     AV_CODEC_ID_DNXHD,
     AV_CODEC_ID_THP,
     AV_CODEC_ID_SGI,
     AV_CODEC_ID_C93,
     AV_CODEC_ID_BETHSOFTVID,
     AV_CODEC_ID_PTX,
     AV_CODEC_ID_TXD,
     AV_CODEC_ID_VP6A,
     AV_CODEC_ID_AMV,
     AV_CODEC_ID_VB,
     AV_CODEC_ID_PCX,
     AV_CODEC_ID_SUNRAST,
     AV_CODEC_ID_INDEO4,
     AV_CODEC_ID_INDEO5,
     AV_CODEC_ID_MIMIC,
     AV_CODEC_ID_RL2,
     AV_CODEC_ID_ESCAPE124,
     AV_CODEC_ID_DIRAC,
     AV_CODEC_ID_BFI,
     AV_CODEC_ID_CMV,
     AV_CODEC_ID_MOTIONPIXELS,
     AV_CODEC_ID_TGV,
     AV_CODEC_ID_TGQ,
     AV_CODEC_ID_TQI,
     AV_CODEC_ID_AURA,
     AV_CODEC_ID_AURA2,
     AV_CODEC_ID_V210X,
     AV_CODEC_ID_TMV,
     AV_CODEC_ID_V210,
     AV_CODEC_ID_DPX,
     AV_CODEC_ID_MAD,
     AV_CODEC_ID_FRWU,
     AV_CODEC_ID_FLASHSV2,
     AV_CODEC_ID_CDGRAPHICS,
     AV_CODEC_ID_R210,
     AV_CODEC_ID_ANM,
     AV_CODEC_ID_BINKVIDEO,
     AV_CODEC_ID_IFF_ILBM,
     AV_CODEC_ID_IFF_BYTERUN1,
     AV_CODEC_ID_KGV1,
     AV_CODEC_ID_YOP,
     AV_CODEC_ID_VP8,
     AV_CODEC_ID_PICTOR,
     AV_CODEC_ID_ANSI,
     AV_CODEC_ID_A64_MULTI,
     AV_CODEC_ID_A64_MULTI5,
     AV_CODEC_ID_R10K,
     AV_CODEC_ID_MXPEG,
     AV_CODEC_ID_LAGARITH,
     AV_CODEC_ID_PRORES,
     AV_CODEC_ID_JV,
     AV_CODEC_ID_DFA,
     AV_CODEC_ID_WMV3IMAGE,
     AV_CODEC_ID_VC1IMAGE,
     AV_CODEC_ID_UTVIDEO,
     AV_CODEC_ID_BMV_VIDEO,
     AV_CODEC_ID_VBLE,
     AV_CODEC_ID_DXTORY,
     AV_CODEC_ID_V410,
     AV_CODEC_ID_XWD,
     AV_CODEC_ID_CDXL,
     AV_CODEC_ID_XBM,
     AV_CODEC_ID_ZEROCODEC,
     AV_CODEC_ID_MSS1,
     AV_CODEC_ID_MSA1,
     AV_CODEC_ID_TSCC2,
     AV_CODEC_ID_MTS2,
     AV_CODEC_ID_CLLC,

     AV_CODEC_ID_MSS2,

     AV_CODEC_ID_BRENDER_PIX= MKBETAG('B','P','I','X'),

     AV_CODEC_ID_Y41P       = MKBETAG('Y','4','1','P'),
     AV_CODEC_ID_ESCAPE130  = MKBETAG('E','1','3','0'),
     AV_CODEC_ID_EXR        = MKBETAG('0','E','X','R'),
     AV_CODEC_ID_AVRP       = MKBETAG('A','V','R','P'),
 

     AV_CODEC_ID_012V       = MKBETAG('0','1','2','V'),

     AV_CODEC_ID_G2M        = MKBETAG( 0 ,'G','2','M'),
     AV_CODEC_ID_AVUI       = MKBETAG('A','V','U','I'),
     AV_CODEC_ID_AYUV       = MKBETAG('A','Y','U','V'),

     AV_CODEC_ID_TARGA_Y216 = MKBETAG('T','2','1','6'),

     AV_CODEC_ID_V308       = MKBETAG('V','3','0','8'),
     AV_CODEC_ID_V408       = MKBETAG('V','4','0','8'),
     AV_CODEC_ID_YUV4       = MKBETAG('Y','U','V','4'),
     AV_CODEC_ID_SANM       = MKBETAG('S','A','N','M'),
     AV_CODEC_ID_PAF_VIDEO  = MKBETAG('P','A','F','V'),

     AV_CODEC_ID_AVRN       = MKBETAG('A','V','R','n'),

     AV_CODEC_ID_CPIA       = MKBETAG('C','P','I','A'),

     AV_CODEC_ID_XFACE      = MKBETAG('X','F','A','C'),

     AV_CODEC_ID_SGIRLE     = MKBETAG('S','G','I','R'),

     AV_CODEC_ID_MVC1       = MKBETAG('M','V','C','1'),
     AV_CODEC_ID_MVC2       = MKBETAG('M','V','C','2'),

     /* various PCM "codecs" */

     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
     AV_CODEC_ID_PCM_S16LE = 0x10000,
     AV_CODEC_ID_PCM_S16BE,
     AV_CODEC_ID_PCM_U16LE,
     AV_CODEC_ID_PCM_U16BE,
     AV_CODEC_ID_PCM_S8,
     AV_CODEC_ID_PCM_U8,
     AV_CODEC_ID_PCM_MULAW,
     AV_CODEC_ID_PCM_ALAW,
     AV_CODEC_ID_PCM_S32LE,
     AV_CODEC_ID_PCM_S32BE,
     AV_CODEC_ID_PCM_U32LE,
     AV_CODEC_ID_PCM_U32BE,
     AV_CODEC_ID_PCM_S24LE,
     AV_CODEC_ID_PCM_S24BE,
     AV_CODEC_ID_PCM_U24LE,
     AV_CODEC_ID_PCM_U24BE,
     AV_CODEC_ID_PCM_S24DAUD,
     AV_CODEC_ID_PCM_ZORK,
     AV_CODEC_ID_PCM_S16LE_PLANAR,
     AV_CODEC_ID_PCM_DVD,
     AV_CODEC_ID_PCM_F32BE,
     AV_CODEC_ID_PCM_F32LE,
     AV_CODEC_ID_PCM_F64BE,
     AV_CODEC_ID_PCM_F64LE,
     AV_CODEC_ID_PCM_BLURAY,
     AV_CODEC_ID_PCM_LXF,
     AV_CODEC_ID_S302M,
     AV_CODEC_ID_PCM_S8_PLANAR,

     AV_CODEC_ID_PCM_S24LE_PLANAR = MKBETAG(24,'P','S','P'),
     AV_CODEC_ID_PCM_S32LE_PLANAR = MKBETAG(32,'P','S','P'),

     AV_CODEC_ID_PCM_S16BE_PLANAR = MKBETAG('P','S','P',16),

     /* various ADPCM codecs */

     AV_CODEC_ID_ADPCM_IMA_QT = 0x11000,
     AV_CODEC_ID_ADPCM_IMA_WAV,
     AV_CODEC_ID_ADPCM_IMA_DK3,
     AV_CODEC_ID_ADPCM_IMA_DK4,
     AV_CODEC_ID_ADPCM_IMA_WS,
     AV_CODEC_ID_ADPCM_IMA_SMJPEG,
     AV_CODEC_ID_ADPCM_MS,
     AV_CODEC_ID_ADPCM_4XM,
     AV_CODEC_ID_ADPCM_XA,
     AV_CODEC_ID_ADPCM_ADX,
     AV_CODEC_ID_ADPCM_EA,
     AV_CODEC_ID_ADPCM_G726,
     AV_CODEC_ID_ADPCM_CT,
     AV_CODEC_ID_ADPCM_SWF,
     AV_CODEC_ID_ADPCM_YAMAHA,
     AV_CODEC_ID_ADPCM_SBPRO_4,
     AV_CODEC_ID_ADPCM_SBPRO_3,
     AV_CODEC_ID_ADPCM_SBPRO_2,
     AV_CODEC_ID_ADPCM_THP,
     AV_CODEC_ID_ADPCM_IMA_AMV,
     AV_CODEC_ID_ADPCM_EA_R1,
     AV_CODEC_ID_ADPCM_EA_R3,
     AV_CODEC_ID_ADPCM_EA_R2,
     AV_CODEC_ID_ADPCM_IMA_EA_SEAD,
     AV_CODEC_ID_ADPCM_IMA_EA_EACS,
     AV_CODEC_ID_ADPCM_EA_XAS,
     AV_CODEC_ID_ADPCM_EA_MAXIS_XA,
     AV_CODEC_ID_ADPCM_IMA_ISS,
     AV_CODEC_ID_ADPCM_G722,
     AV_CODEC_ID_ADPCM_IMA_APC,

     AV_CODEC_ID_VIMA       = MKBETAG('V','I','M','A'),

     AV_CODEC_ID_ADPCM_AFC  = MKBETAG('A','F','C',' '),

     AV_CODEC_ID_ADPCM_IMA_OKI = MKBETAG('O','K','I',' '),

     /* AMR */

     AV_CODEC_ID_AMR_NB = 0x12000,
     AV_CODEC_ID_AMR_WB,

     /* RealAudio codecs*/

     AV_CODEC_ID_RA_144 = 0x13000,
     AV_CODEC_ID_RA_288,

 
     /* various DPCM codecs */

     AV_CODEC_ID_ROQ_DPCM = 0x14000,
     AV_CODEC_ID_INTERPLAY_DPCM,
     AV_CODEC_ID_XAN_DPCM,
     AV_CODEC_ID_SOL_DPCM,

     /* audio codecs */

     AV_CODEC_ID_MP2 = 0x15000,
     AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
     AV_CODEC_ID_AAC,
     AV_CODEC_ID_AC3,
     AV_CODEC_ID_DTS,
     AV_CODEC_ID_VORBIS,
     AV_CODEC_ID_DVAUDIO,
     AV_CODEC_ID_WMAV1,
     AV_CODEC_ID_WMAV2,
     AV_CODEC_ID_MACE3,
     AV_CODEC_ID_MACE6,
     AV_CODEC_ID_VMDAUDIO,
     AV_CODEC_ID_FLAC,
     AV_CODEC_ID_MP3ADU,
     AV_CODEC_ID_MP3ON4,
     AV_CODEC_ID_SHORTEN,
     AV_CODEC_ID_ALAC,
     AV_CODEC_ID_WESTWOOD_SND1,
     AV_CODEC_ID_GSM, ///< as in Berlin toast format
     AV_CODEC_ID_QDM2,
     AV_CODEC_ID_COOK,
     AV_CODEC_ID_TRUESPEECH,
     AV_CODEC_ID_TTA,
     AV_CODEC_ID_SMACKAUDIO,
     AV_CODEC_ID_QCELP,
     AV_CODEC_ID_WAVPACK,
     AV_CODEC_ID_DSICINAUDIO,
     AV_CODEC_ID_IMC,
     AV_CODEC_ID_MUSEPACK7,
     AV_CODEC_ID_MLP,
     AV_CODEC_ID_GSM_MS, /* as found in WAV */
     AV_CODEC_ID_ATRAC3,
     AV_CODEC_ID_VOXWARE,
     AV_CODEC_ID_APE,
     AV_CODEC_ID_NELLYMOSER,
     AV_CODEC_ID_MUSEPACK8,
     AV_CODEC_ID_SPEEX,
     AV_CODEC_ID_WMAVOICE,
     AV_CODEC_ID_WMAPRO,
     AV_CODEC_ID_WMALOSSLESS,
     AV_CODEC_ID_ATRAC3P,
     AV_CODEC_ID_EAC3,
     AV_CODEC_ID_SIPR,
     AV_CODEC_ID_MP1,
     AV_CODEC_ID_TWINVQ,
     AV_CODEC_ID_TRUEHD,
     AV_CODEC_ID_MP4ALS,
     AV_CODEC_ID_ATRAC1,
     AV_CODEC_ID_BINKAUDIO_RDFT,
     AV_CODEC_ID_BINKAUDIO_DCT,
     AV_CODEC_ID_AAC_LATM,
     AV_CODEC_ID_QDMC,
     AV_CODEC_ID_CELT,
     AV_CODEC_ID_G723_1,
     AV_CODEC_ID_G729,
     AV_CODEC_ID_8SVX_EXP,
     AV_CODEC_ID_8SVX_FIB,
     AV_CODEC_ID_BMV_AUDIO,
     AV_CODEC_ID_RALF,
     AV_CODEC_ID_IAC,
     AV_CODEC_ID_ILBC,

     AV_CODEC_ID_OPUS_DEPRECATED,

     AV_CODEC_ID_COMFORT_NOISE,

     AV_CODEC_ID_TAK_DEPRECATED,

     AV_CODEC_ID_FFWAVESYNTH = MKBETAG('F','F','W','S'),

 #if LIBAVCODEC_VERSION_MAJOR <= 54

     AV_CODEC_ID_8SVX_RAW    = MKBETAG('8','S','V','X'),

 #endif

     AV_CODEC_ID_SONIC       = MKBETAG('S','O','N','C'),
     AV_CODEC_ID_SONIC_LS    = MKBETAG('S','O','N','L'),
     AV_CODEC_ID_PAF_AUDIO   = MKBETAG('P','A','F','A'),
     AV_CODEC_ID_OPUS        = MKBETAG('O','P','U','S'),

     AV_CODEC_ID_TAK         = MKBETAG('t','B','a','K'),

     /* subtitle codecs */

     AV_CODEC_ID_FIRST_SUBTITLE = 0x17000,          ///< A dummy ID pointing at the start of subtitle codecs.
     AV_CODEC_ID_DVD_SUBTITLE = 0x17000,
     AV_CODEC_ID_DVB_SUBTITLE,
     AV_CODEC_ID_TEXT,  ///< raw UTF-8 text
     AV_CODEC_ID_XSUB,
     AV_CODEC_ID_SSA,
     AV_CODEC_ID_MOV_TEXT,
     AV_CODEC_ID_HDMV_PGS_SUBTITLE,
     AV_CODEC_ID_DVB_TELETEXT,
     AV_CODEC_ID_SRT,

     AV_CODEC_ID_MICRODVD   = MKBETAG('m','D','V','D'),
     AV_CODEC_ID_EIA_608    = MKBETAG('c','6','0','8'),
     AV_CODEC_ID_JACOSUB    = MKBETAG('J','S','U','B'),
     AV_CODEC_ID_SAMI       = MKBETAG('S','A','M','I'),
     AV_CODEC_ID_REALTEXT   = MKBETAG('R','T','X','T'),

     AV_CODEC_ID_SUBVIEWER1 = MKBETAG('S','b','V','1'),

     AV_CODEC_ID_SUBVIEWER  = MKBETAG('S','u','b','V'),

     AV_CODEC_ID_SUBRIP     = MKBETAG('S','R','i','p'),

     AV_CODEC_ID_WEBVTT     = MKBETAG('W','V','T','T'),

     AV_CODEC_ID_MPL2       = MKBETAG('M','P','L','2'),

     AV_CODEC_ID_VPLAYER    = MKBETAG('V','P','l','r'),

     AV_CODEC_ID_PJS        = MKBETAG('P','h','J','S'),

     /* other specific kind of codecs (generally used for attachments) */

     AV_CODEC_ID_FIRST_UNKNOWN = 0x18000,           ///< A dummy ID pointing at the start of various fake codecs.
     AV_CODEC_ID_TTF = 0x18000,

     AV_CODEC_ID_BINTEXT    = MKBETAG('B','T','X','T'),
     AV_CODEC_ID_XBIN       = MKBETAG('X','B','I','N'),
     AV_CODEC_ID_IDF        = MKBETAG( 0 ,'I','D','F'),

     AV_CODEC_ID_OTF        = MKBETAG( 0 ,'O','T','F'),

     AV_CODEC_ID_SMPTE_KLV  = MKBETAG('K','L','V','A'),

     AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it

     AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS

                                 * stream (only used by libavformat) */

     AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems

                                 * stream (only used by libavformat) */

     AV_CODEC_ID_FFMETADATA = 0x21000,   ///< Dummy codec for streams containing only metadata information.

 
 #if FF_API_CODEC_ID
 #include "old_codec_ids.h"
 #endif

 };

 #if FF_API_CODEC_ID
 #define CodecID AVCodecID
 #endif
 

 /**
  * This struct describes the properties of a single codec described by an
  * AVCodecID.
  * @see avcodec_get_descriptor()
  */
 typedef struct AVCodecDescriptor {
     enum AVCodecID     id;
     enum AVMediaType type;
     /**
      * Name of the codec described by this descriptor. It is non-empty and
      * unique for each codec descriptor. It should contain alphanumeric
      * characters and '_' only.
      */
     const char      *name;
     /**
      * A more descriptive name for this codec. May be NULL.
      */
     const char *long_name;

     /**
      * Codec properties, a combination of AV_CODEC_PROP_* flags.
      */
     int             props;

 } AVCodecDescriptor;
 

 /**
  * Codec uses only intra compression.
  * Video codecs only.
  */
 #define AV_CODEC_PROP_INTRA_ONLY    (1 << 0)

 /**
  * Codec supports lossy compression. Audio and video codecs only.
  * @note a codec may support both lossy and lossless
  * compression modes
  */
 #define AV_CODEC_PROP_LOSSY         (1 << 1)
 /**
  * Codec supports lossless compression. Audio and video codecs only.
  */
 #define AV_CODEC_PROP_LOSSLESS      (1 << 2)

 #if FF_API_OLD_DECODE_AUDIO

 /* in bytes */

 #define AVCODEC_MAX_AUDIO_FRAME_SIZE 192000 // 1 second of 48khz 32bit audio

 #endif

 /**

  * @ingroup lavc_decoding

  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.

  * This is mainly needed because some optimized bitstream readers read
  * 32 or 64 bit at once and could read over the end.<br>

  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
  * MPEG bitstreams could cause overread and segfault.

  */

 #define FF_INPUT_BUFFER_PADDING_SIZE 16

 /**

  * @ingroup lavc_encoding

  * minimum encoding buffer size
  * Used to avoid some checks during header writing.

  */
 #define FF_MIN_BUFFER_SIZE 16384
 

 /**

  * @ingroup lavc_encoding

  * motion estimation type.

  */

 enum Motion_Est_ID {

     ME_ZERO = 1,    ///< no search, that is use 0,0 vector whenever one is needed

     ME_FULL,
     ME_LOG,
     ME_PHODS,

     ME_EPZS,        ///< enhanced predictive zonal search
     ME_X1,          ///< reserved for experiments
     ME_HEX,         ///< hexagon based search
     ME_UMH,         ///< uneven multi-hexagon search
     ME_ITER,        ///< iterative search

     ME_TESA,        ///< transformed exhaustive search algorithm

 };
 

 /**
  * @ingroup lavc_decoding
  */

 enum AVDiscard{

     /* We leave some space between them for extensions (drop some
      * keyframes for intra-only or drop just some bidir frames). */

     AVDISCARD_NONE    =-16, ///< discard nothing
     AVDISCARD_DEFAULT =  0, ///< discard useless packets like 0 size packets in avi
     AVDISCARD_NONREF  =  8, ///< discard all non reference
     AVDISCARD_BIDIR   = 16, ///< discard all bidirectional frames
     AVDISCARD_NONKEY  = 32, ///< discard all frames except keyframes
     AVDISCARD_ALL     = 48, ///< discard all

 };
 

 enum AVColorPrimaries{

     AVCOL_PRI_BT709       = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
     AVCOL_PRI_UNSPECIFIED = 2,
     AVCOL_PRI_BT470M      = 4,
     AVCOL_PRI_BT470BG     = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
     AVCOL_PRI_SMPTE170M   = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
     AVCOL_PRI_SMPTE240M   = 7, ///< functionally identical to above
     AVCOL_PRI_FILM        = 8,
     AVCOL_PRI_NB             , ///< Not part of ABI

 };
 
 enum AVColorTransferCharacteristic{

     AVCOL_TRC_BT709       = 1, ///< also ITU-R BT1361
     AVCOL_TRC_UNSPECIFIED = 2,
     AVCOL_TRC_GAMMA22     = 4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
     AVCOL_TRC_GAMMA28     = 5, ///< also ITU-R BT470BG

     AVCOL_TRC_SMPTE240M   = 7,

     AVCOL_TRC_NB             , ///< Not part of ABI

 };
 
 enum AVColorSpace{

     AVCOL_SPC_RGB         = 0,
     AVCOL_SPC_BT709       = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / SMPTE RP177 Annex B
     AVCOL_SPC_UNSPECIFIED = 2,
     AVCOL_SPC_FCC         = 4,
     AVCOL_SPC_BT470BG     = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM / IEC 61966-2-4 xvYCC601
     AVCOL_SPC_SMPTE170M   = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC / functionally identical to above
     AVCOL_SPC_SMPTE240M   = 7,

     AVCOL_SPC_YCOCG       = 8, ///< Used by Dirac / VC-2 and H.264 FRext, see ITU-T SG16

     AVCOL_SPC_NB             , ///< Not part of ABI

 };

 #define AVCOL_SPC_YCGCO AVCOL_SPC_YCOCG

 
 enum AVColorRange{

     AVCOL_RANGE_UNSPECIFIED = 0,
     AVCOL_RANGE_MPEG        = 1, ///< the normal 219*2^(n-8) "MPEG" YUV ranges
     AVCOL_RANGE_JPEG        = 2, ///< the normal     2^n-1   "JPEG" YUV ranges
     AVCOL_RANGE_NB             , ///< Not part of ABI

 };
 

 /**
  *  X   X      3 4 X      X are luma samples,
  *             1 2        1-6 are possible chroma positions
  *  X   X      5 6 X      0 is undefined/unknown position
  */
 enum AVChromaLocation{

     AVCHROMA_LOC_UNSPECIFIED = 0,
     AVCHROMA_LOC_LEFT        = 1, ///< mpeg2/4, h264 default
     AVCHROMA_LOC_CENTER      = 2, ///< mpeg1, jpeg, h263
     AVCHROMA_LOC_TOPLEFT     = 3, ///< DV
     AVCHROMA_LOC_TOP         = 4,
     AVCHROMA_LOC_BOTTOMLEFT  = 5,
     AVCHROMA_LOC_BOTTOM      = 6,
     AVCHROMA_LOC_NB             , ///< Not part of ABI

 };
 

 enum AVAudioServiceType {
     AV_AUDIO_SERVICE_TYPE_MAIN              = 0,
     AV_AUDIO_SERVICE_TYPE_EFFECTS           = 1,
     AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
     AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED  = 3,
     AV_AUDIO_SERVICE_TYPE_DIALOGUE          = 4,
     AV_AUDIO_SERVICE_TYPE_COMMENTARY        = 5,
     AV_AUDIO_SERVICE_TYPE_EMERGENCY         = 6,
     AV_AUDIO_SERVICE_TYPE_VOICE_OVER        = 7,
     AV_AUDIO_SERVICE_TYPE_KARAOKE           = 8,
     AV_AUDIO_SERVICE_TYPE_NB                   , ///< Not part of ABI
 };
 

 /**
  * @ingroup lavc_encoding
  */

 typedef struct RcOverride{
     int start_frame;
     int end_frame;

     int qscale; // If this is 0 then quality_factor will be used instead.

     float quality_factor;
 } RcOverride;
 

 #define FF_MAX_B_FRAMES 16

 /* encoding support

    These flags can be passed in AVCodecContext.flags before initialization.
    Note: Not everything is supported yet.

 */

 #define CODEC_FLAG_QSCALE 0x0002  ///< Use fixed qscale.
 #define CODEC_FLAG_4MV    0x0004  ///< 4 MV per MB allowed / advanced prediction for H.263.
 #define CODEC_FLAG_QPEL   0x0010  ///< Use qpel MC.
 #define CODEC_FLAG_GMC    0x0020  ///< Use GMC.
 #define CODEC_FLAG_MV0    0x0040  ///< Always try a MB with MV=<0,0>.

 /**
  * The parent program guarantees that the input for B-frames containing

  * streams is not written to for at least s->max_b_frames+1 frames, if

  * this is not set the input will be copied.
  */

 #define CODEC_FLAG_INPUT_PRESERVED 0x0100

 #define CODEC_FLAG_PASS1           0x0200   ///< Use internal 2pass ratecontrol in first pass mode.
 #define CODEC_FLAG_PASS2           0x0400   ///< Use internal 2pass ratecontrol in second pass mode.
 #define CODEC_FLAG_GRAY            0x2000   ///< Only decode/encode grayscale.
 #define CODEC_FLAG_EMU_EDGE        0x4000   ///< Don't draw edges.
 #define CODEC_FLAG_PSNR            0x8000   ///< error[?] variables will be set during encoding.
 #define CODEC_FLAG_TRUNCATED       0x00010000 /** Input bitstream might be truncated at a random
                                                   location instead of only at frame boundaries. */

 #define CODEC_FLAG_NORMALIZE_AQP  0x00020000 ///< Normalize adaptive quantization.
 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
 #define CODEC_FLAG_LOW_DELAY      0x00080000 ///< Force low delay.
 #define CODEC_FLAG_GLOBAL_HEADER  0x00400000 ///< Place global headers in extradata instead of every keyframe.
 #define CODEC_FLAG_BITEXACT       0x00800000 ///< Use only bitexact stuff (except (I)DCT).

 /* Fx : Flag for h263+ extra options */

 #define CODEC_FLAG_AC_PRED        0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction

 #define CODEC_FLAG_LOOP_FILTER    0x00000800 ///< loop filter

 #define CODEC_FLAG_INTERLACED_ME  0x20000000 ///< interlaced motion estimation

 #define CODEC_FLAG_CLOSED_GOP     0x80000000

 #define CODEC_FLAG2_FAST          0x00000001 ///< Allow non spec compliant speedup tricks.
 #define CODEC_FLAG2_NO_OUTPUT     0x00000004 ///< Skip bitstream encoding.
 #define CODEC_FLAG2_LOCAL_HEADER  0x00000008 ///< Place global headers at every keyframe instead of in extradata.

 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format. DEPRECATED!!!!

 #if FF_API_MPV_GLOBAL_OPTS

 #define CODEC_FLAG_CBP_RD         0x04000000 ///< Use rate distortion optimization for cbp.

 #define CODEC_FLAG_QP_RD          0x08000000 ///< Use rate distortion optimization for qp selectioon.

 #define CODEC_FLAG2_STRICT_GOP    0x00000002 ///< Strictly enforce GOP size.

 #define CODEC_FLAG2_SKIP_RD       0x00004000 ///< RD optimal MB level residual skipping

 #endif

 #define CODEC_FLAG2_CHUNKS        0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.

 #define CODEC_FLAG2_SHOW_ALL      0x00400000 ///< Show all frames before the first keyframe

 /* Unsupported options :

  *              Syntax Arithmetic coding (SAC)
  *              Reference Picture Selection

  *              Independent Segment Decoding */

 /* /Fx */

 /* codec capabilities */
 

 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.

 /**

  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
  * If not set, it might not use get_buffer() at all or use operations that
  * assume the buffer was allocated by avcodec_default_get_buffer.

  */
 #define CODEC_CAP_DR1             0x0002

 #define CODEC_CAP_TRUNCATED       0x0008

 /* Codec can export data for HW decoding (XvMC). */

 #define CODEC_CAP_HWACCEL         0x0010

 /**

  * Encoder or decoder requires flushing with NULL input at the end in order to
  * give the complete and correct output.
  *
  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
  *       with NULL data. The user can still send NULL data to the public encode
  *       or decode function, but libavcodec will not pass it along to the codec
  *       unless this flag is set.
  *
  * Decoders:
  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,

  * avpkt->size=0 at the end to get the delayed data until the decoder no longer

  * returns frames.
  *
  * Encoders:
  * The encoder needs to be fed with NULL data at the end of encoding until the
  * encoder no longer returns data.

  *
  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
  *       flag also means that the encoder must set the pts and duration for
  *       each output packet. If this flag is not set, the pts and duration will
  *       be determined by libavcodec from the input frame.

  */

 #define CODEC_CAP_DELAY           0x0020

 /**
  * Codec can be fed a final frame with a smaller size.
  * This can be used to prevent truncation of the last audio samples.
  */
 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040

 /**
  * Codec can export data for HW decoding (VDPAU).
  */
 #define CODEC_CAP_HWACCEL_VDPAU    0x0080

 /**
  * Codec can output multiple frames per AVPacket

  * Normally demuxers return one frame at a time, demuxers which do not do
  * are connected to a parser to split what they return into proper frames.
  * This flag is reserved to the very rare category of codecs which have a
  * bitstream that cannot be split into frames without timeconsuming
  * operations like full decoding. Demuxers carring such bitstreams thus
  * may return multiple frames in a packet. This has many disadvantages like
  * prohibiting stream copy in many cases thus it should only be considered
  * as a last resort.

  */
 #define CODEC_CAP_SUBFRAMES        0x0100

 /**
  * Codec is experimental and is thus avoided in favor of non experimental
  * encoders
  */
 #define CODEC_CAP_EXPERIMENTAL     0x0200

 /**
  * Codec should fill in channel configuration and samplerate instead of container
  */
 #define CODEC_CAP_CHANNEL_CONF     0x0400

 /**
  * Codec is able to deal with negative linesizes
  */
 #define CODEC_CAP_NEG_LINESIZES    0x0800

 /**
  * Codec supports frame-level multithreading.
  */
 #define CODEC_CAP_FRAME_THREADS    0x1000

 /**
  * Codec supports slice-based (or partition-based) multithreading.
  */
 #define CODEC_CAP_SLICE_THREADS    0x2000

 /**

  * Codec supports changed parameters at any point.
  */
 #define CODEC_CAP_PARAM_CHANGE     0x4000

 /**

  * Codec supports avctx->thread_count == 0 (auto).
  */
 #define CODEC_CAP_AUTO_THREADS     0x8000

 /**

  * Audio encoder supports receiving a different number of samples in each call.
  */
 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000

 /**

  * Codec is intra only.
  */
 #define CODEC_CAP_INTRA_ONLY       0x40000000
 /**

  * Codec is lossless.
  */
 #define CODEC_CAP_LOSSLESS         0x80000000

 //The following defines may change, don't expect compatibility if you use them.

 #define MB_TYPE_INTRA4x4   0x0001

 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
 #define MB_TYPE_INTRA_PCM  0x0004 //FIXME H.264-specific

 #define MB_TYPE_16x16      0x0008
 #define MB_TYPE_16x8       0x0010
 #define MB_TYPE_8x16       0x0020
 #define MB_TYPE_8x8        0x0040
 #define MB_TYPE_INTERLACED 0x0080

 #define MB_TYPE_DIRECT2    0x0100 //FIXME

 #define MB_TYPE_ACPRED     0x0200
 #define MB_TYPE_GMC        0x0400
 #define MB_TYPE_SKIP       0x0800
 #define MB_TYPE_P0L0       0x1000
 #define MB_TYPE_P1L0       0x2000
 #define MB_TYPE_P0L1       0x4000
 #define MB_TYPE_P1L1       0x8000
 #define MB_TYPE_L0         (MB_TYPE_P0L0 | MB_TYPE_P1L0)
 #define MB_TYPE_L1         (MB_TYPE_P0L1 | MB_TYPE_P1L1)
 #define MB_TYPE_L0L1       (MB_TYPE_L0   | MB_TYPE_L1)
 #define MB_TYPE_QUANT      0x00010000
 #define MB_TYPE_CBP        0x00020000
 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
 

 /**
  * Pan Scan area.

  * This specifies the area which should be displayed.
  * Note there may be multiple such areas for one frame.

  */
 typedef struct AVPanScan{
     /**

      * id
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */
     int id;
 
     /**
      * width and height in 1/16 pel

      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */
     int width;
     int height;
 
     /**

      * position of the top left corner in 1/16 pel for up to 3 fields/frames
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */
     int16_t position[3][2];
 }AVPanScan;
 

 #define FF_QSCALE_TYPE_MPEG1 0
 #define FF_QSCALE_TYPE_MPEG2 1
 #define FF_QSCALE_TYPE_H264  2

 #define FF_QSCALE_TYPE_VP56  3

 
 #define FF_BUFFER_TYPE_INTERNAL 1

 #define FF_BUFFER_TYPE_USER     2 ///< direct rendering buffers (image is (de)allocated by user)
 #define FF_BUFFER_TYPE_SHARED   4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
 #define FF_BUFFER_TYPE_COPY     8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.

 #define FF_BUFFER_HINTS_VALID    0x01 // Buffer hints value is meaningful (if 0 ignore).
 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).

 /**
  * @defgroup lavc_packet AVPacket
  *
  * Types and functions for working with AVPacket.
  * @{
  */

 enum AVPacketSideDataType {
     AV_PKT_DATA_PALETTE,

     AV_PKT_DATA_NEW_EXTRADATA,

 
     /**
      * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:

      * @code

      * u32le param_flags
      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
      *     s32le channel_count
      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
      *     u64le channel_layout
      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
      *     s32le sample_rate
      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
      *     s32le width
      *     s32le height

      * @endcode

      */

     AV_PKT_DATA_PARAM_CHANGE,

 
     /**
      * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
      * structures with info about macroblocks relevant to splitting the
      * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
      * That is, it does not necessarily contain info about all macroblocks,
      * as long as the distance between macroblocks in the info is smaller
      * than the target payload size.
      * Each MB info structure is 12 bytes, and is laid out as follows:

      * @code

      * u32le bit offset from the start of the packet
      * u8    current quantizer at the start of the macroblock
      * u8    GOB number
      * u16le macroblock address within the GOB
      * u8    horizontal MV predictor
      * u8    vertical MV predictor
      * u8    horizontal MV predictor for block number 3
      * u8    vertical MV predictor for block number 3

      * @endcode

      */

     AV_PKT_DATA_H263_MB_INFO,

 
     /**
      * Recommmends skipping the specified number of samples
      * @code
      * u32le number of samples to skip from start of this packet
      * u32le number of samples to skip from end of this packet
      * u8    reason for start skip
      * u8    reason for end   skip (0=padding silence, 1=convergence)
      * @endcode
      */
     AV_PKT_DATA_SKIP_SAMPLES=70,

 
     /**
      * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
      * the packet may contain "dual mono" audio specific to Japanese DTV
      * and if it is true, recommends only the selected channel to be used.
      * @code
      * u8    selected channels (0=mail/left, 1=sub/right, 2=both)
      * @endcode
      */
     AV_PKT_DATA_JP_DUALMONO,

 
     /**
      * A list of zero terminated key/value strings. There is no end marker for
      * the list, so it is required to rely on the side data size to stop.
      */
     AV_PKT_DATA_STRINGS_METADATA,

 
     /**
      * Subtitle event position
      * @code
      * u32le x1
      * u32le y1
      * u32le x2
      * u32le y2
      * @endcode
      */
     AV_PKT_DATA_SUBTITLE_POSITION,

 };
 

 /**
  * This structure stores compressed data. It is typically exported by demuxers
  * and then passed as input to decoders, or received as output from encoders and
  * then passed to muxers.
  *
  * For video, it should typically contain one compressed frame. For audio it may
  * contain several compressed frames.
  *

  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public

  * ABI. Thus it may be allocated on stack and no new fields can be added to it
  * without libavcodec and libavformat major bump.
  *
  * The semantics of data ownership depends on the destruct field.
  * If it is set, the packet data is dynamically allocated and is valid
  * indefinitely until av_free_packet() is called (which in turn calls the
  * destruct callback to free the data). If destruct is not set, the packet data
  * is typically backed by some static buffer somewhere and is only valid for a
  * limited time (e.g. until the next read call when demuxing).
  *
  * The side data is always allocated with av_malloc() and is freed in
  * av_free_packet().
  */

 typedef struct AVPacket {
     /**

      * Presentation timestamp in AVStream->time_base units; the time at which
      * the decompressed packet will be presented to the user.

      * Can be AV_NOPTS_VALUE if it is not stored in the file.
      * pts MUST be larger or equal to dts as presentation cannot happen before
      * decompression, unless one wants to view hex dumps. Some formats misuse
      * the terms dts and pts/cts to mean something different. Such timestamps
      * must be converted to true pts/dts before they are stored in AVPacket.
      */
     int64_t pts;
     /**

      * Decompression timestamp in AVStream->time_base units; the time at which
      * the packet is decompressed.

      * Can be AV_NOPTS_VALUE if it is not stored in the file.
      */
     int64_t dts;
     uint8_t *data;
     int   size;
     int   stream_index;

     /**
      * A combination of AV_PKT_FLAG values
      */

     int   flags;
     /**

      * Additional packet data that can be provided by the container.
      * Packet can contain several types of side information.
      */
     struct {
         uint8_t *data;
         int      size;
         enum AVPacketSideDataType type;
     } *side_data;
     int side_data_elems;
 
     /**

      * Duration of this packet in AVStream->time_base units, 0 if unknown.

      * Equals next_pts - this_pts in presentation order.
      */
     int   duration;
     void  (*destruct)(struct AVPacket *);
     void  *priv;
     int64_t pos;                            ///< byte position in stream, -1 if unknown
 
     /**

      * Time difference in AVStream->time_base units from the pts of this

      * packet to the point at which the output from the decoder has converged
      * independent from the availability of previous frames. That is, the
      * frames are virtually identical no matter if decoding started from
      * the very first frame or from this keyframe.
      * Is AV_NOPTS_VALUE if unknown.
      * This field is not the display duration of the current packet.

      * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
      * set.

      *
      * The purpose of this field is to allow seeking in streams that have no
      * keyframes in the conventional sense. It corresponds to the
      * recovery point SEI in H.264 and match_time_delta in NUT. It is also
      * essential for some types of subtitle streams to ensure that all
      * subtitles are correctly displayed after seeking.
      */
     int64_t convergence_duration;
 } AVPacket;

 #define AV_PKT_FLAG_KEY     0x0001 ///< The packet contains a keyframe
 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted

 enum AVSideDataParamChangeFlags {
     AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT  = 0x0001,
     AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002,
     AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE    = 0x0004,
     AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS     = 0x0008,
 };

 /**
  * @}
  */

 
 /**

  * This structure describes decoded (raw) audio or video data.
  *
  * AVFrame must be allocated using avcodec_alloc_frame() and freed with
  * avcodec_free_frame(). Note that this allocates only the AVFrame itself. The
  * buffers for the data must be managed through other means.
  *
  * AVFrame is typically allocated once and then reused multiple times to hold
  * different data (e.g. a single AVFrame to hold frames received from a
  * decoder). In such a case, avcodec_get_frame_defaults() should be used to
  * reset the frame to its original clean state before it is reused again.
  *
  * sizeof(AVFrame) is not a part of the public ABI, so new fields may be added
  * to the end with a minor bump.

  * Similarly fields that are marked as to be only accessed by

  * av_opt_ptr() can be reordered. This allows 2 forks to add fields
  * without breaking compatibility with each other.

  */

 typedef struct AVFrame {

 #define AV_NUM_DATA_POINTERS 8

     /**

      * pointer to the picture/channel planes.

      * This might be different from the first allocated byte

      * - encoding: Set by user
      * - decoding: set by AVCodecContext.get_buffer()

      */

     uint8_t *data[AV_NUM_DATA_POINTERS];

 
     /**
      * Size, in bytes, of the data for each picture/channel plane.
      *
      * For audio, only linesize[0] may be set. For planar audio, each channel
      * plane must be the same size.
      *

      * - encoding: Set by user

      * - decoding: set by AVCodecContext.get_buffer()

      */

     int linesize[AV_NUM_DATA_POINTERS];

     /**

      * pointers to the data planes/channels.
      *
      * For video, this should simply point to data[].
      *
      * For planar audio, each channel has a separate data pointer, and
      * linesize[0] contains the size of each channel buffer.
      * For packed audio, there is just one data pointer, and linesize[0]
      * contains the total size of the buffer for all channels.
      *
      * Note: Both data and extended_data will always be set by get_buffer(),
      * but for planar audio with more channels that can fit in data,
      * extended_data must be used by the decoder in order to access all
      * channels.
      *

      * encoding: set by user

      * decoding: set by AVCodecContext.get_buffer()

      */

     uint8_t **extended_data;
 
     /**
      * width and height of the video frame
      * - encoding: unused
      * - decoding: Read by user.
      */
     int width, height;
 
     /**
      * number of audio samples (per channel) described by this frame
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */
     int nb_samples;
 
     /**
      * format of the frame, -1 if unknown or unset

      * Values correspond to enum AVPixelFormat for video frames,

      * enum AVSampleFormat for audio)
      * - encoding: unused
      * - decoding: Read by user.
      */
     int format;
 

     /**
      * 1 -> keyframe, 0-> not
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.
      */
     int key_frame;
 
     /**
      * Picture type of the frame, see ?_TYPE below.
      * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
      * - decoding: Set by libavcodec.
      */
     enum AVPictureType pict_type;
 
     /**

      * pointer to the first allocated byte of the picture. Can be used in get_buffer/release_buffer.
      * This isn't used by libavcodec unless the default get/release_buffer() is used.
      * - encoding:
      * - decoding:
      */
     uint8_t *base[AV_NUM_DATA_POINTERS];
 
     /**

      * sample aspect ratio for the video frame, 0/1 if unknown/unspecified

      * - encoding: unused
      * - decoding: Read by user.
      */
     AVRational sample_aspect_ratio;
 
     /**

      * presentation timestamp in time_base units (time when frame should be shown to user)
      * If AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed.
      * - encoding: MUST be set by user.
      * - decoding: Set by libavcodec.
      */
     int64_t pts;
 
     /**

      * pts copied from the AVPacket that was decoded to produce this frame

      * - encoding: unused
      * - decoding: Read by user.
      */
     int64_t pkt_pts;
 
     /**

      * dts copied from the AVPacket that triggered returning this frame

      * - encoding: unused
      * - decoding: Read by user.
      */
     int64_t pkt_dts;
 
     /**

      * picture number in bitstream order
      * - encoding: set by
      * - decoding: Set by libavcodec.
      */
     int coded_picture_number;
     /**
      * picture number in display order
      * - encoding: set by
      * - decoding: Set by libavcodec.
      */
     int display_picture_number;
 
     /**
      * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
      * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
      * - decoding: Set by libavcodec.
      */
     int quality;
 
     /**
      * is this picture used as reference
      * The values for this are the same as the MpegEncContext.picture_structure
      * variable, that is 1->top field, 2->bottom field, 3->frame/both fields.
      * Set to 4 for delayed, non-reference frames.
      * - encoding: unused
      * - decoding: Set by libavcodec. (before get_buffer() call)).
      */
     int reference;
 
     /**
      * QP table
      * - encoding: unused
      * - decoding: Set by libavcodec.
      */
     int8_t *qscale_table;
     /**
      * QP store stride
      * - encoding: unused
      * - decoding: Set by libavcodec.
      */
     int qstride;
 
     /**

      *
      */
     int qscale_type;
 
     /**

      * mbskip_table[mb]>=1 if MB didn't change
      * stride= mb_width = (width+15)>>4
      * - encoding: unused
      * - decoding: Set by libavcodec.
      */
     uint8_t *mbskip_table;
 
     /**
      * motion vector table
      * @code
      * example:
      * int mv_sample_log2= 4 - motion_subsample_log2;
      * int mb_width= (width+15)>>4;
      * int mv_stride= (mb_width << mv_sample_log2) + 1;
      * motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];
      * @endcode
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     int16_t (*motion_val[2])[2];
 
     /**
      * macroblock type table
      * mb_type_base + mb_width + 2
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     uint32_t *mb_type;
 
     /**

      * DCT coefficients

      * - encoding: unused
      * - decoding: Set by libavcodec.
      */

     short *dct_coeff;
 
     /**
      * motion reference frame index
      * the order in which these are stored can depend on the codec.
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     int8_t *ref_index[2];

 
     /**
      * for some private data of the user
      * - encoding: unused
      * - decoding: Set by user.
      */
     void *opaque;
 
     /**
      * error
      * - encoding: Set by libavcodec. if flags&CODEC_FLAG_PSNR.
      * - decoding: unused
      */

     uint64_t error[AV_NUM_DATA_POINTERS];

 
     /**
      * type of the buffer (to keep track of who has to deallocate data[*])
      * - encoding: Set by the one who allocates it.
      * - decoding: Set by the one who allocates it.
      * Note: User allocated (direct rendering) & internal buffers cannot coexist currently.
      */
     int type;
 
     /**
      * When decoding, this signals how much the picture must be delayed.
      * extra_delay = repeat_pict / (2*fps)
      * - encoding: unused
      * - decoding: Set by libavcodec.
      */
     int repeat_pict;
 
     /**
      * The content of the picture is interlaced.
      * - encoding: Set by user.
      * - decoding: Set by libavcodec. (default 0)
      */
     int interlaced_frame;
 
     /**
      * If the content is interlaced, is top field displayed first.
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     int top_field_first;
 
     /**
      * Tell user application that palette has changed from previous frame.
      * - encoding: ??? (no palette-enabled encoder yet)
      * - decoding: Set by libavcodec. (default 0).
      */
     int palette_has_changed;
 
     /**
      * codec suggestion on buffer type if != 0
      * - encoding: unused
      * - decoding: Set by libavcodec. (before get_buffer() call)).
      */
     int buffer_hints;
 
     /**

      * Pan scan.

      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */

     AVPanScan *pan_scan;

 
     /**
      * reordered opaque 64bit (generally an integer or a double precision float
      * PTS but can be anything).
      * The user sets AVCodecContext.reordered_opaque to represent the input at
      * that time,
      * the decoder reorders values as needed and sets AVFrame.reordered_opaque
      * to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
      * @deprecated in favor of pkt_pts
      * - encoding: unused
      * - decoding: Read by user.
      */
     int64_t reordered_opaque;
 
     /**

      * hardware accelerator private data (FFmpeg-allocated)

      * - encoding: unused
      * - decoding: Set by libavcodec
      */
     void *hwaccel_picture_private;
 
     /**
      * the AVCodecContext which ff_thread_get_buffer() was last called on
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.
      */
     struct AVCodecContext *owner;
 
     /**
      * used by multithreading to store frame-specific info
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.
      */
     void *thread_opaque;

 
     /**

      * log2 of the size of the block which a single vector in motion_val represents:
      * (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)

      * - encoding: unused

      * - decoding: Set by libavcodec.

      */

     uint8_t motion_subsample_log2;

 
     /**

      * Sample rate of the audio data.
      *
      * - encoding: unused

      * - decoding: read by user

      */
     int sample_rate;
 
     /**
      * Channel layout of the audio data.
      *
      * - encoding: unused

      * - decoding: read by user.

      */
     uint64_t channel_layout;

 
     /**

      * frame timestamp estimated using various heuristics, in stream time base

      * Code outside libavcodec should access this field using:

      * av_frame_get_best_effort_timestamp(frame)

      * - encoding: unused

      * - decoding: set by libavcodec, read by user.

      */

     int64_t best_effort_timestamp;

 
     /**

      * reordered pos from the last AVPacket that has been input into the decoder

      * Code outside libavcodec should access this field using:

      * av_frame_get_pkt_pos(frame)

      * - encoding: unused
      * - decoding: Read by user.
      */

     int64_t pkt_pos;

     /**
      * duration of the corresponding packet, expressed in
      * AVStream->time_base units, 0 if unknown.
      * Code outside libavcodec should access this field using:
      * av_frame_get_pkt_duration(frame)
      * - encoding: unused
      * - decoding: Read by user.
      */
     int64_t pkt_duration;

 
     /**
      * metadata.
      * Code outside libavcodec should access this field using:
      * av_frame_get_metadata(frame)
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     AVDictionary *metadata;

 
     /**
      * decode error flags of the frame, set to a combination of
      * FF_DECODE_ERROR_xxx flags if the decoder produced a frame, but there
      * were errors during the decoding.
      * Code outside libavcodec should access this field using:
      * av_frame_get_decode_error_flags(frame)
      * - encoding: unused
      * - decoding: set by libavcodec, read by user.
      */
     int decode_error_flags;
 #define FF_DECODE_ERROR_INVALID_BITSTREAM   1
 #define FF_DECODE_ERROR_MISSING_REFERENCE   2

 
     /**
      * number of audio channels, only used for audio.
      * Code outside libavcodec should access this field using:
      * av_frame_get_channels(frame)
      * - encoding: unused
      * - decoding: Read by user.
      */
     int64_t channels;

 
     /**
      * size of the corresponding packet containing the compressed
      * frame. It must be accessed using av_frame_get_pkt_size() and
      * av_frame_set_pkt_size().
      * It is set to a negative value if unknown.
      * - encoding: unused
      * - decoding: set by libavcodec, read by user.
      */
     int pkt_size;

 } AVFrame;

 /**
  * Accessors for some AVFrame fields.
  * The position of these field in the structure is not part of the ABI,
  * they should not be accessed directly outside libavcodec.
  */
 int64_t av_frame_get_best_effort_timestamp(const AVFrame *frame);
 void    av_frame_set_best_effort_timestamp(AVFrame *frame, int64_t val);

 int64_t av_frame_get_pkt_duration         (const AVFrame *frame);

 void    av_frame_set_pkt_duration         (AVFrame *frame, int64_t val);

 int64_t av_frame_get_pkt_pos              (const AVFrame *frame);

 void    av_frame_set_pkt_pos              (AVFrame *frame, int64_t val);

 int64_t av_frame_get_channel_layout       (const AVFrame *frame);

 void    av_frame_set_channel_layout       (AVFrame *frame, int64_t val);

 int     av_frame_get_channels             (const AVFrame *frame);
 void    av_frame_set_channels             (AVFrame *frame, int     val);

 int     av_frame_get_sample_rate          (const AVFrame *frame);

 void    av_frame_set_sample_rate          (AVFrame *frame, int     val);

 AVDictionary *av_frame_get_metadata       (const AVFrame *frame);
 void          av_frame_set_metadata       (AVFrame *frame, AVDictionary *val);

 int     av_frame_get_decode_error_flags   (const AVFrame *frame);
 void    av_frame_set_decode_error_flags   (AVFrame *frame, int     val);

 int     av_frame_get_pkt_size(const AVFrame *frame);
 void    av_frame_set_pkt_size(AVFrame *frame, int val);

 struct AVCodecInternal;
 

 enum AVFieldOrder {
     AV_FIELD_UNKNOWN,
     AV_FIELD_PROGRESSIVE,
     AV_FIELD_TT,          //< Top coded_first, top displayed first
     AV_FIELD_BB,          //< Bottom coded first, bottom displayed first
     AV_FIELD_TB,          //< Top coded first, bottom displayed first
     AV_FIELD_BT,          //< Bottom coded first, top displayed first
 };
 

 /**

  * main external API structure.
  * New fields can be added to the end with minor version bumps.

  * Removal, reordering and changes to existing fields require a major

  * version bump.

  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user

  * applications.

  * sizeof(AVCodecContext) must not be used outside libav*.

  */

 typedef struct AVCodecContext {

     /**

      * information on struct for av_log

      * - set by avcodec_alloc_context3

      */

     const AVClass *av_class;

     int log_level_offset;
 
     enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */

     const struct AVCodec  *codec;

     char             codec_name[32];

     enum AVCodecID     codec_id; /* see AV_CODEC_ID_xxx */

 
     /**
      * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
      * This is used to work around some encoder bugs.
      * A demuxer should set this to what is stored in the field used to identify the codec.
      * If there are multiple such fields in a container then the demuxer should choose the one
      * which maximizes the information about the used codec.
      * If the codec tag field in a container is larger than 32 bits then the demuxer should
      * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
      * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
      * first.
      * - encoding: Set by user, if not then the default based on codec_id will be used.
      * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
      */
     unsigned int codec_tag;
 
     /**
      * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
      * This is used to work around some encoder bugs.
      * - encoding: unused
      * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
      */
     unsigned int stream_codec_tag;
 

 #if FF_API_SUB_ID

     /**

      * @deprecated this field is unused

      */

     attribute_deprecated int sub_id;
 #endif

 
     void *priv_data;
 
     /**
      * Private context used for internal data.
      *
      * Unlike priv_data, this is not codec-specific. It is used in general
      * libavcodec functions.
      */
     struct AVCodecInternal *internal;
 
     /**
      * Private data of the user, can be used to carry app specific stuff.
      * - encoding: Set by user.
      * - decoding: Set by user.
      */
     void *opaque;
 

     /**

      * the average bitrate
      * - encoding: Set by user; unused for constant quantizer encoding.
      * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.

      */

     int bit_rate;

 
     /**

      * number of bits the bitstream is allowed to diverge from the reference.

      *           the reference can be CBR (for CBR pass1) or VBR (for pass2)

      * - encoding: Set by user; unused for constant quantizer encoding.

      * - decoding: unused

      */

     int bit_rate_tolerance;

 
     /**

      * Global quality for codecs which cannot change it per frame.
      * This should be proportional to MPEG-1/2/4 qscale.

      * - encoding: Set by user.

      * - decoding: unused

      */

     int global_quality;

 
     /**

      * - encoding: Set by user.
      * - decoding: unused

      */

     int compression_level;
 #define FF_COMPRESSION_DEFAULT -1

 
     /**

      * CODEC_FLAG_*.
      * - encoding: Set by user.
      * - decoding: Set by user.

      */

     int flags;
 
     /**
      * CODEC_FLAG2_*
      * - encoding: Set by user.
      * - decoding: Set by user.
      */
     int flags2;

 
     /**

      * some codecs need / can use extradata like Huffman tables.
      * mjpeg: Huffman tables

      * rv10: additional flags

      * mpeg4: global headers (they can be in the bitstream or here)

      * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
      * than extradata_size to avoid prolems if it is read with the bitstream reader.
      * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
      * - encoding: Set/allocated/freed by libavcodec.
      * - decoding: Set/allocated/freed by user.

      */

     uint8_t *extradata;

     int extradata_size;

     /**

      * This is the fundamental unit of time (in seconds) in terms
      * of which frame timestamps are represented. For fixed-fps content,

      * timebase should be 1/framerate and timestamp increments should be
      * identically 1.

      * - encoding: MUST be set by user.
      * - decoding: Set by libavcodec.

      */

     AVRational time_base;

     /**
      * For some codecs, the time base is closer to the field rate than the frame rate.
      * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
      * if no telecine is used ...
      *
      * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
      */
     int ticks_per_frame;
 
     /**

      * Codec delay.

      *

      * Encoding: Number of frames delay there will be from the encoder input to
      *           the decoder output. (we assume the decoder matches the spec)
      * Decoding: Number of frames delay in addition to what a standard decoder
      *           as specified in the spec would produce.

      *
      * Video:
      *   Number of frames the decoded output will be delayed relative to the
      *   encoded input.
      *
      * Audio:

      *   For encoding, this is the number of "priming" samples added to the
      *   beginning of the stream. The decoded output will be delayed by this
      *   many samples relative to the input to the encoder. Note that this
      *   field is purely informational and does not directly affect the pts
      *   output by the encoder, which should always be based on the actual
      *   presentation time, including any delay.
      *   For decoding, this is the number of samples the decoder needs to
      *   output before the decoder's output is valid. When seeking, you should
      *   start decoding this many samples prior to your desired seek point.

      *
      * - encoding: Set by libavcodec.

      * - decoding: Set by libavcodec.

      */
     int delay;
 
 

     /* video only */

     /**

      * picture width / height.

      * - encoding: MUST be set by user.

      * - decoding: Set by libavcodec.
      * Note: For compatibility it is possible to set this instead of
      * coded_width/height before decoding.

      */

     int width, height;

     /**

      * Bitstream width / height, may be different from width/height if lowres enabled.

      * - encoding: unused
      * - decoding: Set by user before init if known. Codec should override / dynamically change if needed.
      */
     int coded_width, coded_height;
 

 #define FF_ASPECT_EXTENDED 15

 
     /**

      * the number of pictures in a group of pictures, or 0 for intra_only
      * - encoding: Set by user.

      * - decoding: unused

      */
     int gop_size;
 
     /**

      * Pixel format, see AV_PIX_FMT_xxx.

      * May be set by the demuxer if known from headers.

      * May be overridden by the decoder if it knows better.

      * - encoding: Set by user.

      * - decoding: Set by user if known, overridden by libavcodec if known

      */

     enum AVPixelFormat pix_fmt;

     /**

      * Motion estimation algorithm used for video coding.
      * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
      * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
      * - encoding: MUST be set by user.
      * - decoding: unused
      */
     int me_method;
 
     /**

      * If non NULL, 'draw_horiz_band' is called by the libavcodec
      * decoder to draw a horizontal band. It improves cache usage. Not

      * all codecs can do that. You must check the codec capabilities

      * beforehand.

      * When multithreading is used, it may be called from multiple threads
      * at the same time; threads might draw different parts of the same AVFrame,
      * or multiple AVFrames, and there is no guarantee that slices will be drawn
      * in order.

      * The function is also used by hardware acceleration APIs.
      * It is called at least once during frame decoding to pass
      * the data needed for hardware render.
      * In that mode instead of pixel data, AVFrame points to
      * a structure specific to the acceleration API. The application
      * reads the structure and can change some fields to indicate progress
      * or mark state.

      * - encoding: unused

      * - decoding: Set by user.

      * @param height the height of the slice
      * @param y the y position of the slice
      * @param type 1->top field, 2->bottom field, 3->frame
      * @param offset offset into the AVFrame.data from which the slice should be read

      */

     void (*draw_horiz_band)(struct AVCodecContext *s,

                             const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],

                             int y, int type, int height);

     /**

      * callback to negotiate the pixelFormat
      * @param fmt is the list of formats which are supported by the codec,
      * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
      * The first is always the native one.
      * @return the chosen format
      * - encoding: unused
      * - decoding: Set by user, if not set the native format will be chosen.

      */

     enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);

 
     /**

      * maximum number of B-frames between non-B-frames
      * Note: The output will be delayed by max_b_frames+1 relative to the input.
      * - encoding: Set by user.

      * - decoding: unused

      */
     int max_b_frames;
 
     /**

      * qscale factor between IP and B-frames

      * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
      * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).

      * - encoding: Set by user.

      * - decoding: unused

      */
     float b_quant_factor;

     /** obsolete FIXME remove */
     int rc_strategy;

 #define FF_RC_STRATEGY_XVID 1
 

     int b_frame_strategy;

 #if FF_API_MPV_GLOBAL_OPTS

     /**

      * luma single coefficient elimination threshold
      * - encoding: Set by user.

      * - decoding: unused

      */

     attribute_deprecated int luma_elim_threshold;

     /**

      * chroma single coeff elimination threshold
      * - encoding: Set by user.

      * - decoding: unused

      */

     attribute_deprecated int chroma_elim_threshold;
 #endif

     /**

      * qscale offset between IP and B-frames
      * - encoding: Set by user.

      * - decoding: unused

      */
     float b_quant_offset;

     /**

      * Size of the frame reordering buffer in the decoder.

      * For MPEG-2 it is 1 IPB or 0 low delay IP.

      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.

      */
     int has_b_frames;

 
     /**

      * 0-> h263 quant 1-> mpeg quant
      * - encoding: Set by user.

      * - decoding: unused

      */
     int mpeg_quant;

     /**

      * qscale factor between P and I-frames
      * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
      * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
      * - encoding: Set by user.

      * - decoding: unused

      */
     float i_quant_factor;

     /**

      * qscale offset between P and I-frames
      * - encoding: Set by user.

      * - decoding: unused

      */
     float i_quant_offset;

     /**

      * luminance masking (0-> disabled)
      * - encoding: Set by user.

      * - decoding: unused

      */
     float lumi_masking;

     /**

      * temporary complexity masking (0-> disabled)
      * - encoding: Set by user.

      * - decoding: unused

      */
     float temporal_cplx_masking;

     /**

      * spatial complexity masking (0-> disabled)
      * - encoding: Set by user.

      * - decoding: unused

      */
     float spatial_cplx_masking;

     /**

      * p block masking (0-> disabled)
      * - encoding: Set by user.

      * - decoding: unused

      */
     float p_masking;

     /**

      * darkness masking (0-> disabled)
      * - encoding: Set by user.

      * - decoding: unused

      */
     float dark_masking;

     /**

      * slice count
      * - encoding: Set by libavcodec.
      * - decoding: Set by user (or 0).

      */
     int slice_count;
     /**

      * prediction method (needed for huffyuv)
      * - encoding: Set by user.

      * - decoding: unused

      */
      int prediction_method;
 #define FF_PRED_LEFT   0
 #define FF_PRED_PLANE  1
 #define FF_PRED_MEDIAN 2

     /**

      * slice offsets in the frame in bytes
      * - encoding: Set/allocated by libavcodec.
      * - decoding: Set/allocated by user (or NULL).
      */
     int *slice_offset;
 
     /**

      * sample aspect ratio (0 if unknown)

      * That is the width of a pixel divided by the height of the pixel.

      * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */

     AVRational sample_aspect_ratio;

 
     /**

      * motion estimation comparison function
      * - encoding: Set by user.

      * - decoding: unused

      */
     int me_cmp;
     /**

      * subpixel motion estimation comparison function
      * - encoding: Set by user.

      * - decoding: unused

      */
     int me_sub_cmp;
     /**

      * macroblock comparison function (not supported yet)
      * - encoding: Set by user.

      * - decoding: unused

      */
     int mb_cmp;

     /**

      * interlaced DCT comparison function
      * - encoding: Set by user.

      * - decoding: unused
      */
     int ildct_cmp;

 #define FF_CMP_SAD    0
 #define FF_CMP_SSE    1
 #define FF_CMP_SATD   2
 #define FF_CMP_DCT    3
 #define FF_CMP_PSNR   4
 #define FF_CMP_BIT    5
 #define FF_CMP_RD     6
 #define FF_CMP_ZERO   7
 #define FF_CMP_VSAD   8
 #define FF_CMP_VSSE   9
 #define FF_CMP_NSSE   10
 #define FF_CMP_W53    11
 #define FF_CMP_W97    12

 #define FF_CMP_DCTMAX 13

 #define FF_CMP_DCT264 14

 #define FF_CMP_CHROMA 256

     /**

      * ME diamond size & shape
      * - encoding: Set by user.

      * - decoding: unused

      */
     int dia_size;

 
     /**

      * amount of previous MV predictors (2a+1 x 2a+1 square)
      * - encoding: Set by user.

      * - decoding: unused

      */
     int last_predictor_count;

     /**

      * prepass for motion estimation
      * - encoding: Set by user.

      * - decoding: unused

      */
     int pre_me;

     /**

      * motion estimation prepass comparison function
      * - encoding: Set by user.

      * - decoding: unused

      */
     int me_pre_cmp;

     /**

      * ME prepass diamond size & shape
      * - encoding: Set by user.

      * - decoding: unused

      */
     int pre_dia_size;
 

     /**

      * subpel ME quality
      * - encoding: Set by user.

      * - decoding: unused

      */
     int me_subpel_quality;
 

     /**

      * DTG active format information (additional aspect ratio
      * information only used in DVB MPEG-2 transport streams)
      * 0 if not set.

      *

      * - encoding: unused
      * - decoding: Set by decoder.

      */
     int dtg_active_format;
 #define FF_DTG_AFD_SAME         8
 #define FF_DTG_AFD_4_3          9
 #define FF_DTG_AFD_16_9         10
 #define FF_DTG_AFD_14_9         11
 #define FF_DTG_AFD_4_3_SP_14_9  13
 #define FF_DTG_AFD_16_9_SP_14_9 14
 #define FF_DTG_AFD_SP_4_3       15
 

     /**

      * maximum motion estimation search range in subpel units
      * If 0 then no limit.

      *

      * - encoding: Set by user.
      * - decoding: unused

      */

     int me_range;

     /**

      * intra quantizer bias
      * - encoding: Set by user.

      * - decoding: unused
      */
     int intra_quant_bias;
 #define FF_DEFAULT_QUANT_BIAS 999999

     /**

      * inter quantizer bias
      * - encoding: Set by user.

      * - decoding: unused
      */
     int inter_quant_bias;

 #if FF_API_COLOR_TABLE_ID

     /**

      * color table ID
      * - encoding: unused
      * - decoding: Which clrtable should be used for 8bit RGB images.
      *             Tables have to be stored somewhere. FIXME

      */

     attribute_deprecated int color_table_id;
 #endif

     /**

      * slice flags
      * - encoding: unused

      * - decoding: Set by user.

      */
     int slice_flags;
 #define SLICE_FLAG_CODED_ORDER    0x0001 ///< draw_horiz_band() is called in coded order instead of display
 #define SLICE_FLAG_ALLOW_FIELD    0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
 #define SLICE_FLAG_ALLOW_PLANE    0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
 

     /**
      * XVideo Motion Acceleration
      * - encoding: forbidden
      * - decoding: set by decoder
      */
     int xvmc_acceleration;

     /**
      * macroblock decision mode

      * - encoding: Set by user.

      * - decoding: unused
      */
     int mb_decision;
 #define FF_MB_DECISION_SIMPLE 0        ///< uses mb_cmp
 #define FF_MB_DECISION_BITS   1        ///< chooses the one which needs the fewest bits

 #define FF_MB_DECISION_RD     2        ///< rate distortion

 
     /**
      * custom intra quantization matrix

      * - encoding: Set by user, can be NULL.
      * - decoding: Set by libavcodec.

      */
     uint16_t *intra_matrix;
 
     /**
      * custom inter quantization matrix

      * - encoding: Set by user, can be NULL.
      * - decoding: Set by libavcodec.

      */
     uint16_t *inter_matrix;

     /**

      * scene change detection threshold
      * 0 is default, larger means fewer detected scene changes.
      * - encoding: Set by user.

      * - decoding: unused
      */
     int scenechange_threshold;

 
     /**

      * noise reduction strength

      * - encoding: Set by user.

      * - decoding: unused
      */

     int noise_reduction;

 #if FF_API_INTER_THRESHOLD

     /**

      * @deprecated this field is unused

      */

     attribute_deprecated int inter_threshold;
 #endif

 #if FF_API_MPV_GLOBAL_OPTS

     /**

      * @deprecated use mpegvideo private options instead

      */

     attribute_deprecated int quantizer_noise_shaping;
 #endif

     /**

      * Motion estimation threshold below which no motion estimation is
      * performed, but instead the user specified motion vectors are used.
      *
      * - encoding: Set by user.
      * - decoding: unused

      */

     int me_threshold;

 
     /**

      * Macroblock threshold below which the user specified macroblock types will be used.

      * - encoding: Set by user.

      * - decoding: unused
      */

     int mb_threshold;

 
     /**

      * precision of the intra DC coefficient - 8

      * - encoding: Set by user.

      * - decoding: unused
      */

     int intra_dc_precision;

 
     /**

      * Number of macroblock rows at the top which are skipped.
      * - encoding: unused

      * - decoding: Set by user.

      */

     int skip_top;

 
     /**

      * Number of macroblock rows at the bottom which are skipped.
      * - encoding: unused
      * - decoding: Set by user.
      */
     int skip_bottom;
 
     /**
      * Border processing masking, raises the quantizer for mbs on the borders
      * of the picture.

      * - encoding: Set by user.
      * - decoding: unused

      */

     float border_masking;

     /**

      * minimum MB lagrange multipler

      * - encoding: Set by user.

      * - decoding: unused
      */

     int mb_lmin;

 
     /**

      * maximum MB lagrange multipler

      * - encoding: Set by user.

      * - decoding: unused

      */

     int mb_lmax;

     /**

      *
      * - encoding: Set by user.
      * - decoding: unused

      */

     int me_penalty_compensation;

     /**

      *
      * - encoding: Set by user.
      * - decoding: unused

      */

     int bidir_refine;

 
     /**

      *

      * - encoding: Set by user.

      * - decoding: unused

      */

     int brd_scale;

 
     /**

      * minimum GOP size

      * - encoding: Set by user.

      * - decoding: unused
      */

     int keyint_min;

 
     /**

      * number of reference frames

      * - encoding: Set by user.

      * - decoding: Set by lavc.

      */

     int refs;

 
     /**

      * chroma qp offset from luma

      * - encoding: Set by user.

      * - decoding: unused
      */

     int chromaoffset;

 
     /**

      * Multiplied by qscale for each frame and added to scene_change_score.
      * - encoding: Set by user.
      * - decoding: unused

      */

     int scenechange_factor;

 
     /**

      *
      * Note: Value depends upon the compare function used for fullpel ME.
      * - encoding: Set by user.
      * - decoding: unused

      */

     int mv0_threshold;

 
     /**

      * Adjust sensitivity of b_frame_strategy 1.

      * - encoding: Set by user.

      * - decoding: unused

      */

     int b_sensitivity;

     /**
      * Chromaticity coordinates of the source primaries.
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */
     enum AVColorPrimaries color_primaries;

     /**
      * Color Transfer Characteristic.
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */
     enum AVColorTransferCharacteristic color_trc;

     /**
      * YUV colorspace type.
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */
     enum AVColorSpace colorspace;

     /**
      * MPEG vs JPEG YUV range.
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */
     enum AVColorRange color_range;

     /**
      * This defines the location of chroma samples.
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */
     enum AVChromaLocation chroma_sample_location;

     /**
      * Number of slices.
      * Indicates number of picture subdivisions. Used for parallelized
      * decoding.
      * - encoding: Set by user
      * - decoding: unused
      */
     int slices;

     /** Field order
      * - encoding: set by libavcodec

      * - decoding: Set by user.

      */
     enum AVFieldOrder field_order;
 
     /* audio only */
     int sample_rate; ///< samples per second
     int channels;    ///< number of audio channels

     /**

      * audio sample format

      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */

     enum AVSampleFormat sample_fmt;  ///< sample format

     /* The following data should not be initialized. */

     /**

      * Number of samples per channel in an audio frame.
      *
      * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
      *   except the last must contain exactly frame_size samples per channel.
      *   May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
      *   frame size is not restricted.
      * - decoding: may be set by some decoders to indicate constant frame size

      */
     int frame_size;

 
     /**
      * Frame counter, set by libavcodec.
      *
      * - decoding: total number of frames returned from the decoder so far.
      * - encoding: total number of frames passed to the encoder so far.
      *
      *   @note the counter is not incremented if encoding/decoding resulted in
      *   an error.
      */
     int frame_number;

 
     /**
      * number of bytes per packet if constant and known or 0
      * Used by some WAV based audio codecs.
      */
     int block_align;
 
     /**
      * Audio cutoff bandwidth (0 means "automatic")
      * - encoding: Set by user.
      * - decoding: unused
      */
     int cutoff;
 
 #if FF_API_REQUEST_CHANNELS
     /**
      * Decoder should decode to this many channels if it can (0 for default)

      * - encoding: unused

      * - decoding: Set by user.

      * @deprecated Deprecated in favor of request_channel_layout.

      */

     int request_channels;
 #endif

 
     /**

      * Audio channel layout.
      * - encoding: set by user.

      * - decoding: set by user, may be overwritten by libavcodec.

      */
     uint64_t channel_layout;
 
     /**
      * Request decoder to use this channel layout if it can (0 for default)

      * - encoding: unused

      * - decoding: Set by user.

      */

     uint64_t request_channel_layout;

 
     /**

      * Type of service that the audio stream conveys.

      * - encoding: Set by user.

      * - decoding: Set by libavcodec.

      */

     enum AVAudioServiceType audio_service_type;

 
     /**

      * desired sample format
      * - encoding: Not used.

      * - decoding: Set by user.

      * Decoder will decode to this format if it can.

      */
     enum AVSampleFormat request_sample_fmt;
 
     /**
      * Called at the beginning of each frame to get a buffer for it.
      *
      * The function will set AVFrame.data[], AVFrame.linesize[].
      * AVFrame.extended_data[] must also be set, but it should be the same as
      * AVFrame.data[] except for planar audio with more channels than can fit
      * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
      * many data pointers as it can hold.
      *
      * if CODEC_CAP_DR1 is not set then get_buffer() must call
      * avcodec_default_get_buffer() instead of providing buffers allocated by
      * some other means.
      *
      * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
      * need it. avcodec_default_get_buffer() aligns the output buffer properly,
      * but if get_buffer() is overridden then alignment considerations should
      * be taken into account.
      *
      * @see avcodec_default_get_buffer()
      *
      * Video:
      *
      * If pic.reference is set then the frame will be read later by libavcodec.
      * avcodec_align_dimensions2() should be used to find the required width and
      * height, as they normally need to be rounded up to the next multiple of 16.
      *
      * If frame multithreading is used and thread_safe_callbacks is set,
      * it may be called from a different thread, but not from more than one at
      * once. Does not need to be reentrant.
      *
      * @see release_buffer(), reget_buffer()
      * @see avcodec_align_dimensions2()
      *
      * Audio:
      *
      * Decoders request a buffer of a particular size by setting
      * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
      * however, utilize only part of the buffer by setting AVFrame.nb_samples
      * to a smaller value in the output frame.
      *
      * Decoders cannot use the buffer after returning from
      * avcodec_decode_audio4(), so they will not call release_buffer(), as it

      * is assumed to be released immediately upon return. In some rare cases,
      * a decoder may need to call get_buffer() more than once in a single
      * call to avcodec_decode_audio4(). In that case, when get_buffer() is
      * called again after it has already been called once, the previously
      * acquired buffer is assumed to be released at that time and may not be
      * reused by the decoder.

      *
      * As a convenience, av_samples_get_buffer_size() and
      * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
      * functions to find the required data size and to fill data pointers and
      * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
      * since all planes must be the same size.
      *
      * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
      *
      * - encoding: unused
      * - decoding: Set by libavcodec, user can override.
      */
     int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
 
     /**
      * Called to release buffers which were allocated with get_buffer.
      * A released buffer can be reused in get_buffer().
      * pic.data[*] must be set to NULL.
      * May be called from a different thread if frame multithreading is used,
      * but not by more than one thread at once, so does not need to be reentrant.
      * - encoding: unused
      * - decoding: Set by libavcodec, user can override.
      */
     void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
 
     /**
      * Called at the beginning of a frame to get cr buffer for it.
      * Buffer type (size, hints) must be the same. libavcodec won't check it.
      * libavcodec will pass previous buffer in pic, function should return
      * same buffer or new buffer with old frame "painted" into it.
      * If pic.data[0] == NULL must behave like get_buffer().
      * if CODEC_CAP_DR1 is not set then reget_buffer() must call
      * avcodec_default_reget_buffer() instead of providing buffers allocated by
      * some other means.
      * - encoding: unused
      * - decoding: Set by libavcodec, user can override.
      */
     int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
 
 
     /* - encoding parameters */
     float qcompress;  ///< amount of qscale change between easy & hard scenes (0.0-1.0)
     float qblur;      ///< amount of qscale smoothing over time (0.0-1.0)
 
     /**
      * minimum quantizer

      * - encoding: Set by user.

      * - decoding: unused
      */

     int qmin;

 
     /**

      * maximum quantizer

      * - encoding: Set by user.

      * - decoding: unused
      */

     int qmax;

 
     /**

      * maximum quantizer difference between frames

      * - encoding: Set by user.

      * - decoding: unused
      */

     int max_qdiff;

 
     /**

      * ratecontrol qmin qmax limiting method

      * 0-> clipping, 1-> use a nice continuous function to limit qscale wthin qmin/qmax.

      * - encoding: Set by user.

      * - decoding: unused
      */

     float rc_qsquish;
 
     float rc_qmod_amp;
     int rc_qmod_freq;

 
     /**

      * decoder bitstream buffer size

      * - encoding: Set by user.

      * - decoding: unused
      */

     int rc_buffer_size;

 
     /**

      * ratecontrol override, see RcOverride
      * - encoding: Allocated/set/freed by user.

      * - decoding: unused
      */

     int rc_override_count;
     RcOverride *rc_override;

 
     /**

      * rate control equation
      * - encoding: Set by user
      * - decoding: unused
      */
     const char *rc_eq;
 
     /**
      * maximum bitrate

      * - encoding: Set by user.

      * - decoding: unused
      */

     int rc_max_rate;

 
     /**

      * minimum bitrate
      * - encoding: Set by user.
      * - decoding: unused

      */

     int rc_min_rate;
 
     float rc_buffer_aggressivity;

 
     /**

      * initial complexity for pass1 ratecontrol
      * - encoding: Set by user.
      * - decoding: unused

      */

     float rc_initial_cplx;

 
     /**

      * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
      * - encoding: Set by user.
      * - decoding: unused.

      */

     float rc_max_available_vbv_use;

 
     /**

      * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.

      * - encoding: Set by user.

      * - decoding: unused.

      */

     float rc_min_vbv_overflow_use;

 
     /**

      * Number of bits which should be loaded into the rc buffer before decoding starts.

      * - encoding: Set by user.

      * - decoding: unused
      */

     int rc_initial_buffer_occupancy;

 #define FF_CODER_TYPE_VLC       0
 #define FF_CODER_TYPE_AC        1
 #define FF_CODER_TYPE_RAW       2
 #define FF_CODER_TYPE_RLE       3
 #define FF_CODER_TYPE_DEFLATE   4

     /**

      * coder type

      * - encoding: Set by user.

      * - decoding: unused
      */

     int coder_type;

 
     /**

      * context model

      * - encoding: Set by user.

      * - decoding: unused

      */

     int context_model;

 
     /**

      * minimum Lagrange multipler

      * - encoding: Set by user.

      * - decoding: unused
      */

     int lmin;

 
     /**

      * maximum Lagrange multipler

      * - encoding: Set by user.

      * - decoding: unused
      */

     int lmax;

     /**

      * frame skip threshold

      * - encoding: Set by user.

      * - decoding: unused
      */

     int frame_skip_threshold;

 
     /**

      * frame skip factor

      * - encoding: Set by user.

      * - decoding: unused
      */

     int frame_skip_factor;

 
     /**

      * frame skip exponent

      * - encoding: Set by user.

      * - decoding: unused
      */

     int frame_skip_exp;

 
     /**

      * frame skip comparison function

      * - encoding: Set by user.

      * - decoding: unused
      */

     int frame_skip_cmp;

 
     /**

      * trellis RD quantization

      * - encoding: Set by user.

      * - decoding: unused
      */

     int trellis;

 
     /**

      * - encoding: Set by user.
      * - decoding: unused

      */

     int min_prediction_order;

 
     /**

      * - encoding: Set by user.
      * - decoding: unused

      */

     int max_prediction_order;
 

     /**

      * GOP timecode frame start number
      * - encoding: Set by user, in non drop frame format
      * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)

      */
     int64_t timecode_frame_start;

     /* The RTP callback: This function is called    */
     /* every time the encoder has a packet to send. */
     /* It depends on the encoder if the data starts */
     /* with a Start Code (it should). H.263 does.   */
     /* mb_nb contains the number of macroblocks     */
     /* encoded in the RTP payload.                  */
     void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
 
     int rtp_payload_size;   /* The size of the RTP payload: the coder will  */
                             /* do its best to deliver a chunk with size     */
                             /* below rtp_payload_size, the chunk will start */
                             /* with a start code on some codecs like H.263. */
                             /* This doesn't take account of any particular  */
                             /* headers inside the transmitted RTP payload.  */
 
     /* statistics, used for 2-pass encoding */
     int mv_bits;
     int header_bits;
     int i_tex_bits;
     int p_tex_bits;
     int i_count;
     int p_count;
     int skip_count;
     int misc_bits;
 

     /**

      * number of bits used for the previously encoded frame
      * - encoding: Set by libavcodec.
      * - decoding: unused

      */

     int frame_bits;

     /**

      * pass1 encoding statistics output buffer
      * - encoding: Set by libavcodec.
      * - decoding: unused

      */

     char *stats_out;

 
     /**

      * pass2 encoding statistics input buffer
      * Concatenated stuff from stats_out of pass1 should be placed here.
      * - encoding: Allocated/set/freed by user.
      * - decoding: unused

      */

     char *stats_in;

 
     /**

      * Work around bugs in encoders which sometimes cannot be detected automatically.
      * - encoding: Set by user
      * - decoding: Set by user

      */

     int workaround_bugs;
 #define FF_BUG_AUTODETECT       1  ///< autodetection
 #define FF_BUG_OLD_MSMPEG4      2
 #define FF_BUG_XVID_ILACE       4
 #define FF_BUG_UMP4             8
 #define FF_BUG_NO_PADDING       16
 #define FF_BUG_AMV              32
 #define FF_BUG_AC_VLC           0  ///< Will be removed, libavcodec can now handle these non-compliant files by default.
 #define FF_BUG_QPEL_CHROMA      64
 #define FF_BUG_STD_QPEL         128
 #define FF_BUG_QPEL_CHROMA2     256
 #define FF_BUG_DIRECT_BLOCKSIZE 512
 #define FF_BUG_EDGE             1024
 #define FF_BUG_HPEL_CHROMA      2048
 #define FF_BUG_DC_CLIP          4096
 #define FF_BUG_MS               8192 ///< Work around various bugs in Microsoft's broken decoders.
 #define FF_BUG_TRUNCATED       16384

 
     /**

      * strictly follow the standard (MPEG4, ...).
      * - encoding: Set by user.
      * - decoding: Set by user.
      * Setting this to STRICT or higher means the encoder and decoder will
      * generally do stupid things, whereas setting it to unofficial or lower
      * will mean the encoder might produce output that is not supported by all
      * spec-compliant decoders. Decoders don't differentiate between normal,
      * unofficial and experimental (that is, they always try to decode things
      * when they can) unless they are explicitly asked to behave stupidly
      * (=strictly conform to the specs)
      */
     int strict_std_compliance;
 #define FF_COMPLIANCE_VERY_STRICT   2 ///< Strictly conform to an older more strict version of the spec or reference software.
 #define FF_COMPLIANCE_STRICT        1 ///< Strictly conform to all the things in the spec no matter what consequences.
 #define FF_COMPLIANCE_NORMAL        0
 #define FF_COMPLIANCE_UNOFFICIAL   -1 ///< Allow unofficial extensions
 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
 
     /**
      * error concealment flags

      * - encoding: unused
      * - decoding: Set by user.
      */

     int error_concealment;
 #define FF_EC_GUESS_MVS   1
 #define FF_EC_DEBLOCK     2

 
     /**

      * debug

      * - encoding: Set by user.

      * - decoding: Set by user.

      */

     int debug;
 #define FF_DEBUG_PICT_INFO   1
 #define FF_DEBUG_RC          2
 #define FF_DEBUG_BITSTREAM   4
 #define FF_DEBUG_MB_TYPE     8
 #define FF_DEBUG_QP          16
 #define FF_DEBUG_MV          32
 #define FF_DEBUG_DCT_COEFF   0x00000040
 #define FF_DEBUG_SKIP        0x00000080
 #define FF_DEBUG_STARTCODE   0x00000100
 #define FF_DEBUG_PTS         0x00000200
 #define FF_DEBUG_ER          0x00000400
 #define FF_DEBUG_MMCO        0x00000800
 #define FF_DEBUG_BUGS        0x00001000
 #define FF_DEBUG_VIS_QP      0x00002000
 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
 #define FF_DEBUG_BUFFERS     0x00008000
 #define FF_DEBUG_THREADS     0x00010000

 
     /**

      * debug

      * - encoding: Set by user.

      * - decoding: Set by user.

      */

     int debug_mv;
 #define FF_DEBUG_VIS_MV_P_FOR  0x00000001 //visualize forward predicted MVs of P frames
 #define FF_DEBUG_VIS_MV_B_FOR  0x00000002 //visualize forward predicted MVs of B frames
 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
 
     /**
      * Error recognition; may misdetect some more or less valid parts as errors.
      * - encoding: unused
      * - decoding: Set by user.
      */
     int err_recognition;
 #define AV_EF_CRCCHECK  (1<<0)
 #define AV_EF_BITSTREAM (1<<1)
 #define AV_EF_BUFFER    (1<<2)
 #define AV_EF_EXPLODE   (1<<3)
 

 #define AV_EF_CAREFUL    (1<<16)
 #define AV_EF_COMPLIANT  (1<<17)
 #define AV_EF_AGGRESSIVE (1<<18)
 
 

     /**
      * opaque 64bit number (generally a PTS) that will be reordered and
      * output in AVFrame.reordered_opaque
      * @deprecated in favor of pkt_pts
      * - encoding: unused
      * - decoding: Set by user.
      */
     int64_t reordered_opaque;

 
     /**
      * Hardware accelerator in use
      * - encoding: unused.
      * - decoding: Set by libavcodec
      */
     struct AVHWAccel *hwaccel;

 
     /**

      * Hardware accelerator context.
      * For some hardware accelerators, a global context needs to be
      * provided by the user. In that case, this holds display-dependent
      * data FFmpeg cannot instantiate itself. Please refer to the
      * FFmpeg HW accelerator documentation to know how to fill this
      * is. e.g. for VA API, this is a struct vaapi_context.
      * - encoding: unused
      * - decoding: Set by user
      */
     void *hwaccel_context;

 
     /**

      * error
      * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
      * - decoding: unused

      */

     uint64_t error[AV_NUM_DATA_POINTERS];

 
     /**

      * DCT algorithm, see FF_DCT_* below
      * - encoding: Set by user.
      * - decoding: unused

      */

     int dct_algo;
 #define FF_DCT_AUTO    0
 #define FF_DCT_FASTINT 1
 #define FF_DCT_INT     2
 #define FF_DCT_MMX     3
 #define FF_DCT_ALTIVEC 5
 #define FF_DCT_FAAN    6

 
     /**

      * IDCT algorithm, see FF_IDCT_* below.
      * - encoding: Set by user.
      * - decoding: Set by user.

      */

     int idct_algo;
 #define FF_IDCT_AUTO          0
 #define FF_IDCT_INT           1
 #define FF_IDCT_SIMPLE        2
 #define FF_IDCT_SIMPLEMMX     3
 #define FF_IDCT_LIBMPEG2MMX   4

 #if FF_API_MMI

 #define FF_IDCT_MMI           5

 #endif

 #define FF_IDCT_ARM           7
 #define FF_IDCT_ALTIVEC       8
 #define FF_IDCT_SH4           9
 #define FF_IDCT_SIMPLEARM     10
 #define FF_IDCT_H264          11
 #define FF_IDCT_VP3           12
 #define FF_IDCT_IPP           13
 #define FF_IDCT_XVIDMMX       14
 #define FF_IDCT_CAVS          15
 #define FF_IDCT_SIMPLEARMV5TE 16
 #define FF_IDCT_SIMPLEARMV6   17
 #define FF_IDCT_SIMPLEVIS     18
 #define FF_IDCT_WMV2          19
 #define FF_IDCT_FAAN          20
 #define FF_IDCT_EA            21
 #define FF_IDCT_SIMPLENEON    22
 #define FF_IDCT_SIMPLEALPHA   23
 #define FF_IDCT_BINK          24

 #if FF_API_DSP_MASK

     /**

      * Unused.
      * @deprecated use av_set_cpu_flags_mask() instead.

      */

     attribute_deprecated unsigned dsp_mask;
 #endif

 
     /**

      * bits per sample/pixel from the demuxer (needed for huffyuv).
      * - encoding: Set by libavcodec.
      * - decoding: Set by user.

      */

      int bits_per_coded_sample;

 
     /**

      * Bits per sample/pixel of internal libavcodec pixel/sample format.
      * - encoding: set by user.
      * - decoding: set by libavcodec.

      */

     int bits_per_raw_sample;

     /**

      * low resolution decoding, 1-> 1/2 size, 2->1/4 size
      * - encoding: unused
      * - decoding: Set by user.

      */

      int lowres;

 
     /**

      * the picture in the bitstream
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.

      */

     AVFrame *coded_frame;

 
     /**

      * thread count
      * is used to decide how many independent tasks should be passed to execute()
      * - encoding: Set by user.
      * - decoding: Set by user.

      */

     int thread_count;

     /**
      * Which multithreading methods to use.
      * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
      * so clients which cannot provide future frames should not use it.
      *
      * - encoding: Set by user, otherwise the default is used.
      * - decoding: Set by user, otherwise the default is used.
      */
     int thread_type;

 #define FF_THREAD_FRAME   1 ///< Decode more than one frame at once
 #define FF_THREAD_SLICE   2 ///< Decode more than one part of a single frame at once

 
     /**
      * Which multithreading methods are in use by the codec.
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.
      */
     int active_thread_type;
 
     /**
      * Set by the client if its custom get_buffer() callback can be called

      * synchronously from another thread, which allows faster multithreaded decoding.

      * draw_horiz_band() will be called from other threads regardless of this setting.
      * Ignored if the default get_buffer() is used.
      * - encoding: Set by user.
      * - decoding: Set by user.
      */
     int thread_safe_callbacks;
 
     /**

      * The codec may call this to execute several independent things.
      * It will return only after finishing all tasks.
      * The user may replace this with some multithreaded implementation,
      * the default implementation will execute the parts serially.
      * @param count the number of things to execute
      * - encoding: Set by libavcodec, user can override.
      * - decoding: Set by libavcodec, user can override.

      */

     int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);

 
     /**

      * The codec may call this to execute several independent things.
      * It will return only after finishing all tasks.
      * The user may replace this with some multithreaded implementation,
      * the default implementation will execute the parts serially.
      * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
      * @param c context passed also to func
      * @param count the number of things to execute
      * @param arg2 argument passed unchanged to func
      * @param ret return values of executed functions, must have space for "count" values. May be NULL.
      * @param func function that will be called count times, with jobnr from 0 to count-1.
      *             threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
      *             two instances of func executing at the same time will have the same threadnr.
      * @return always 0 currently, but code should handle a future improvement where when any call to func
      *         returns < 0 no further calls to func may be done and < 0 is returned.
      * - encoding: Set by libavcodec, user can override.
      * - decoding: Set by libavcodec, user can override.
      */
     int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
 
     /**
      * thread opaque
      * Can be used by execute() to store some per AVCodecContext stuff.
      * - encoding: set by execute()
      * - decoding: set by execute()
      */
     void *thread_opaque;
 
     /**
      * noise vs. sse weight for the nsse comparsion function
      * - encoding: Set by user.
      * - decoding: unused
      */
      int nsse_weight;
 
     /**
      * profile

      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */

      int profile;
 #define FF_PROFILE_UNKNOWN -99
 #define FF_PROFILE_RESERVED -100
 
 #define FF_PROFILE_AAC_MAIN 0
 #define FF_PROFILE_AAC_LOW  1
 #define FF_PROFILE_AAC_SSR  2
 #define FF_PROFILE_AAC_LTP  3

 #define FF_PROFILE_AAC_HE   4
 #define FF_PROFILE_AAC_HE_V2 28
 #define FF_PROFILE_AAC_LD   22
 #define FF_PROFILE_AAC_ELD  38

 
 #define FF_PROFILE_DTS         20
 #define FF_PROFILE_DTS_ES      30
 #define FF_PROFILE_DTS_96_24   40
 #define FF_PROFILE_DTS_HD_HRA  50
 #define FF_PROFILE_DTS_HD_MA   60
 
 #define FF_PROFILE_MPEG2_422    0
 #define FF_PROFILE_MPEG2_HIGH   1
 #define FF_PROFILE_MPEG2_SS     2
 #define FF_PROFILE_MPEG2_SNR_SCALABLE  3
 #define FF_PROFILE_MPEG2_MAIN   4
 #define FF_PROFILE_MPEG2_SIMPLE 5
 
 #define FF_PROFILE_H264_CONSTRAINED  (1<<9)  // 8+1; constraint_set1_flag
 #define FF_PROFILE_H264_INTRA        (1<<11) // 8+3; constraint_set3_flag
 
 #define FF_PROFILE_H264_BASELINE             66
 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
 #define FF_PROFILE_H264_MAIN                 77
 #define FF_PROFILE_H264_EXTENDED             88
 #define FF_PROFILE_H264_HIGH                 100
 #define FF_PROFILE_H264_HIGH_10              110
 #define FF_PROFILE_H264_HIGH_10_INTRA        (110|FF_PROFILE_H264_INTRA)
 #define FF_PROFILE_H264_HIGH_422             122
 #define FF_PROFILE_H264_HIGH_422_INTRA       (122|FF_PROFILE_H264_INTRA)
 #define FF_PROFILE_H264_HIGH_444             144
 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE  244
 #define FF_PROFILE_H264_HIGH_444_INTRA       (244|FF_PROFILE_H264_INTRA)
 #define FF_PROFILE_H264_CAVLC_444            44
 
 #define FF_PROFILE_VC1_SIMPLE   0
 #define FF_PROFILE_VC1_MAIN     1
 #define FF_PROFILE_VC1_COMPLEX  2
 #define FF_PROFILE_VC1_ADVANCED 3
 
 #define FF_PROFILE_MPEG4_SIMPLE                     0
 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE            1
 #define FF_PROFILE_MPEG4_CORE                       2
 #define FF_PROFILE_MPEG4_MAIN                       3
 #define FF_PROFILE_MPEG4_N_BIT                      4
 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE           5
 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION      6
 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE     7
 #define FF_PROFILE_MPEG4_HYBRID                     8
 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME         9
 #define FF_PROFILE_MPEG4_CORE_SCALABLE             10
 #define FF_PROFILE_MPEG4_ADVANCED_CODING           11
 #define FF_PROFILE_MPEG4_ADVANCED_CORE             12
 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO             14
 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE           15

 
     /**

      * level
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */

      int level;
 #define FF_LEVEL_UNKNOWN -99

 
     /**

      *

      * - encoding: unused
      * - decoding: Set by user.
      */

     enum AVDiscard skip_loop_filter;

     /**

      *

      * - encoding: unused
      * - decoding: Set by user.
      */

     enum AVDiscard skip_idct;

     /**

      *

      * - encoding: unused
      * - decoding: Set by user.

      */

     enum AVDiscard skip_frame;

     /**
      * Header containing style information for text subtitles.
      * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
      * [Script Info] and [V4+ Styles] section, plus the [Events] line and
      * the Format line following. It shouldn't include any Dialogue line.
      * - encoding: Set/allocated/freed by user (before avcodec_open2())
      * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())

      */

     uint8_t *subtitle_header;
     int subtitle_header_size;
 
     /**
      * Simulates errors in the bitstream to test error concealment.
      * - encoding: Set by user.
      * - decoding: unused
      */
     int error_rate;
 
     /**
      * Current packet as passed into the decoder, to avoid having
      * to pass the packet into every function. Currently only valid
      * inside lavc and get/release_buffer callbacks.
      * - decoding: set by avcodec_decode_*, read by get_buffer() for setting pkt_pts
      * - encoding: unused
      */
     AVPacket *pkt;
 
     /**
      * VBV delay coded in the last frame (in periods of a 27 MHz clock).
      * Used for compliant TS muxing.
      * - encoding: Set by libavcodec.
      * - decoding: unused.
      */
     uint64_t vbv_delay;

     /**

      * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
      * Code outside libavcodec should access this field using:
      * avcodec_set_pkt_timebase(avctx)
      * - encoding unused.
      * - decodimg set by user
      */
     AVRational pkt_timebase;
 
     /**

      * AVCodecDescriptor
      * Code outside libavcodec should access this field using:
      * avcodec_get_codec_descriptior(avctx)
      * - encoding: unused.
      * - decoding: set by libavcodec.
      */

     const AVCodecDescriptor *codec_descriptor;

 
     /**

      * Current statistics for PTS correction.

      * - decoding: maintained and used by libavcodec, not intended to be used by user apps

      * - encoding: unused
      */
     int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
     int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
     int64_t pts_correction_last_pts;       /// PTS of the last frame
     int64_t pts_correction_last_dts;       /// DTS of the last frame

 
     /**
      * Current frame metadata.
      * - decoding: maintained and used by libavcodec, not intended to be used by user apps
      * - encoding: unused
      */
     AVDictionary *metadata;

 } AVCodecContext;
 

 AVRational av_codec_get_pkt_timebase         (const AVCodecContext *avctx);
 void       av_codec_set_pkt_timebase         (AVCodecContext *avctx, AVRational val);
 

 const AVCodecDescriptor *av_codec_get_codec_descriptor(const AVCodecContext *avctx);
 void                     av_codec_set_codec_descriptor(AVCodecContext *avctx, const AVCodecDescriptor *desc);

 /**

  * AVProfile.
  */
 typedef struct AVProfile {
     int profile;
     const char *name; ///< short name for the profile
 } AVProfile;
 

 typedef struct AVCodecDefault AVCodecDefault;
 

 struct AVSubtitle;
 

 /**

  * AVCodec.
  */

 typedef struct AVCodec {

     /**
      * Name of the codec implementation.
      * The name is globally unique among encoders and among decoders (but an
      * encoder and a decoder can share the same name).
      * This is the primary way to find a codec from the user perspective.
      */

     const char *name;

     /**
      * Descriptive name for the codec, meant to be more human readable than name.
      * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
      */
     const char *long_name;

     enum AVMediaType type;

     enum AVCodecID id;

     /**
      * Codec capabilities.
      * see CODEC_CAP_*
      */

     int capabilities;

     const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}

     const enum AVPixelFormat *pix_fmts;     ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1

     const int *supported_samplerates;       ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0

     const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1

     const uint64_t *channel_layouts;         ///< array of support channel layouts, or NULL if unknown. array is terminated by 0

     uint8_t max_lowres;                     ///< maximum value for lowres supported by the decoder

     const AVClass *priv_class;              ///< AVClass for the private context

     const AVProfile *profiles;              ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}

     /*****************************************************************
      * No fields below this line are part of the public API. They
      * may not be used outside of libavcodec and can be changed and
      * removed at will.
      * New public fields should be added right above.
      *****************************************************************
      */
     int priv_data_size;
     struct AVCodec *next;

     /**

      * @name Frame-level threading support functions

      * @{
      */
     /**
      * If defined, called on thread contexts when they are created.
      * If the codec allocates writable tables in init(), re-allocate them here.
      * priv_data will be set to a copy of the original.
      */
     int (*init_thread_copy)(AVCodecContext *);
     /**
      * Copy necessary context variables from a previous thread context to the current one.
      * If not defined, the next thread will start automatically; otherwise, the codec
      * must call ff_thread_finish_setup().
      *
      * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
      */
     int (*update_thread_context)(AVCodecContext *dst, const AVCodecContext *src);
     /** @} */

 
     /**
      * Private codec-specific defaults.
      */
     const AVCodecDefault *defaults;

 
     /**
      * Initialize codec static data, called from avcodec_register().
      */
     void (*init_static_data)(struct AVCodec *codec);

     int (*init)(AVCodecContext *);

     int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
                       const struct AVSubtitle *sub);

     /**
      * Encode data to an AVPacket.
      *
      * @param      avctx          codec context
      * @param      avpkt          output AVPacket (may contain a user-provided buffer)
      * @param[in]  frame          AVFrame containing the raw data to be encoded
      * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
      *                            non-empty packet was returned in avpkt.
      * @return 0 on success, negative error code on failure
      */
     int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
                    int *got_packet_ptr);

     int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
     int (*close)(AVCodecContext *);
     /**
      * Flush buffers.
      * Will be called when seeking
      */
     void (*flush)(AVCodecContext *);

 } AVCodec;
 

 /**

  * AVHWAccel.
  */
 typedef struct AVHWAccel {
     /**
      * Name of the hardware accelerated codec.
      * The name is globally unique among encoders and among decoders (but an
      * encoder and a decoder can share the same name).
      */
     const char *name;
 
     /**
      * Type of codec implemented by the hardware accelerator.
      *

      * See AVMEDIA_TYPE_xxx

      */

     enum AVMediaType type;

 
     /**
      * Codec implemented by the hardware accelerator.
      *

      * See AV_CODEC_ID_xxx

      */

     enum AVCodecID id;

 
     /**
      * Supported pixel format.
      *
      * Only hardware accelerated formats are supported here.
      */

     enum AVPixelFormat pix_fmt;

 
     /**
      * Hardware accelerated codec capabilities.
      * see FF_HWACCEL_CODEC_CAP_*
      */
     int capabilities;
 
     struct AVHWAccel *next;
 
     /**
      * Called at the beginning of each frame or field picture.
      *
      * Meaningful frame information (codec specific) is guaranteed to
      * be parsed at this point. This function is mandatory.
      *

      * Note that buf can be NULL along with buf_size set to 0.

      * Otherwise, this means the whole frame is available at this point.
      *
      * @param avctx the codec context
      * @param buf the frame data buffer base
      * @param buf_size the size of the frame in bytes
      * @return zero if successful, a negative value otherwise
      */
     int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
 
     /**
      * Callback for each slice.
      *
      * Meaningful slice information (codec specific) is guaranteed to
      * be parsed at this point. This function is mandatory.
      *
      * @param avctx the codec context
      * @param buf the slice data buffer base
      * @param buf_size the size of the slice in bytes
      * @return zero if successful, a negative value otherwise
      */
     int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
 
     /**
      * Called at the end of each frame or field picture.
      *
      * The whole picture is parsed at this point and can now be sent
      * to the hardware accelerator. This function is mandatory.
      *
      * @param avctx the codec context
      * @return zero if successful, a negative value otherwise
      */
     int (*end_frame)(AVCodecContext *avctx);

 
     /**
      * Size of HW accelerator private data.
      *

      * Private data is allocated with av_mallocz() before
      * AVCodecContext.get_buffer() and deallocated after
      * AVCodecContext.release_buffer().

      */
     int priv_data_size;

 } AVHWAccel;
 
 /**

  * @defgroup lavc_picture AVPicture
  *
  * Functions for working with AVPicture
  * @{
  */
 
 /**

  * four components are given, that's all.
  * the last component is alpha
  */

 typedef struct AVPicture {

     uint8_t *data[AV_NUM_DATA_POINTERS];
     int linesize[AV_NUM_DATA_POINTERS];     ///< number of bytes per line

 } AVPicture;
 

 /**
  * @}
  */
 

 enum AVSubtitleType {
     SUBTITLE_NONE,
 
     SUBTITLE_BITMAP,                ///< A bitmap, pict will be set
 
     /**
      * Plain text, the text field must be set by the decoder and is
      * authoritative. ass and pict fields may contain approximations.
      */
     SUBTITLE_TEXT,
 
     /**
      * Formatted text, the ass field must be set by the decoder and is
      * authoritative. pict and text fields may contain approximations.
      */
     SUBTITLE_ASS,
 };
 

 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
 

 typedef struct AVSubtitleRect {

     int x;         ///< top left corner  of pict, undefined when pict is not set
     int y;         ///< top left corner  of pict, undefined when pict is not set
     int w;         ///< width            of pict, undefined when pict is not set
     int h;         ///< height           of pict, undefined when pict is not set
     int nb_colors; ///< number of colors in pict, undefined when pict is not set

 
     /**
      * data+linesize for the bitmap of this subtitle.
      * can be set for text/ass as well once they where rendered
      */
     AVPicture pict;

     enum AVSubtitleType type;
 
     char *text;                     ///< 0 terminated plain UTF-8 text
 
     /**
      * 0 terminated ASS/SSA compatible event line.

      * The presentation of this is unaffected by the other values in this

      * struct.
      */
     char *ass;

     int flags;

 } AVSubtitleRect;
 
 typedef struct AVSubtitle {
     uint16_t format; /* 0 = graphics */
     uint32_t start_display_time; /* relative to packet pts, in ms */
     uint32_t end_display_time; /* relative to packet pts, in ms */

     unsigned num_rects;

     AVSubtitleRect **rects;

     int64_t pts;    ///< Same as packet pts, in AV_TIME_BASE

 } AVSubtitle;
 

 /**

  * If c is NULL, returns the first registered codec,
  * if c is non-NULL, returns the next registered codec after c,
  * or NULL if c is the last one.

  */

 AVCodec *av_codec_next(const AVCodec *c);

 
 /**

  * Return the LIBAVCODEC_VERSION_INT constant.

  */

 unsigned avcodec_version(void);

 
 /**

  * Return the libavcodec build-time configuration.

  */

 const char *avcodec_configuration(void);

 
 /**

  * Return the libavcodec license.

  */

 const char *avcodec_license(void);

 
 /**

  * Register the codec codec and initialize libavcodec.

  *

  * @warning either this function or avcodec_register_all() must be called
  * before any other libavcodec functions.

  *

  * @see avcodec_register_all()

  */

 void avcodec_register(AVCodec *codec);

 /**

  * Register all the codecs, parsers and bitstream filters which were enabled at
  * configuration time. If you do not call this function you can select exactly
  * which formats you want to support, by using the individual registration
  * functions.

  *

  * @see avcodec_register
  * @see av_register_codec_parser
  * @see av_register_bitstream_filter

  */

 void avcodec_register_all(void);

 #if FF_API_ALLOC_CONTEXT

 /**

  * Allocate an AVCodecContext and set its fields to default values.  The
  * resulting struct can be deallocated by simply calling av_free().

  *

  * @return An AVCodecContext filled with default values or NULL on failure.
  * @see avcodec_get_context_defaults

  *

  * @deprecated use avcodec_alloc_context3()

  */

 attribute_deprecated
 AVCodecContext *avcodec_alloc_context(void);

 /** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
  *  we WILL change its arguments and name a few times! */
 attribute_deprecated
 AVCodecContext *avcodec_alloc_context2(enum AVMediaType);

 
 /**

  * Set the fields of the given AVCodecContext to default values.

  *

  * @param s The AVCodecContext of which the fields should be set to default values.
  * @deprecated use avcodec_get_context_defaults3

  */

 attribute_deprecated
 void avcodec_get_context_defaults(AVCodecContext *s);

 /** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
  *  we WILL change its arguments and name a few times! */
 attribute_deprecated
 void avcodec_get_context_defaults2(AVCodecContext *s, enum AVMediaType);
 #endif

 
 /**

  * Allocate an AVCodecContext and set its fields to default values.  The
  * resulting struct can be deallocated by calling avcodec_close() on it followed
  * by av_free().

  *

  * @param codec if non-NULL, allocate private data and initialize defaults
  *              for the given codec. It is illegal to then call avcodec_open2()
  *              with a different codec.
  *              If NULL, then the codec-specific defaults won't be initialized,
  *              which may result in suboptimal default settings (this is
  *              important mainly for encoders, e.g. libx264).

  *

  * @return An AVCodecContext filled with default values or NULL on failure.
  * @see avcodec_get_context_defaults

  */

 AVCodecContext *avcodec_alloc_context3(const AVCodec *codec);

 /**

  * Set the fields of the given AVCodecContext to default values corresponding
  * to the given codec (defaults may be codec-dependent).

  *

  * Do not call this function if a non-NULL codec has been passed
  * to avcodec_alloc_context3() that allocated this AVCodecContext.
  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
  * different codec on this AVCodecContext.

  */

 int avcodec_get_context_defaults3(AVCodecContext *s, const AVCodec *codec);

 /**

  * Get the AVClass for AVCodecContext. It can be used in combination with
  * AV_OPT_SEARCH_FAKE_OBJ for examining options.

  *

  * @see av_opt_find().

  */

 const AVClass *avcodec_get_class(void);

 /**

  * Get the AVClass for AVFrame. It can be used in combination with
  * AV_OPT_SEARCH_FAKE_OBJ for examining options.

  *

  * @see av_opt_find().

  */

 const AVClass *avcodec_get_frame_class(void);

 
 /**

  * Get the AVClass for AVSubtitleRect. It can be used in combination with
  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
  *
  * @see av_opt_find().
  */
 const AVClass *avcodec_get_subtitle_rect_class(void);
 
 /**

  * Copy the settings of the source AVCodecContext into the destination
  * AVCodecContext. The resulting destination codec context will be
  * unopened, i.e. you are required to call avcodec_open2() before you
  * can use this AVCodecContext to decode/encode video/audio data.

  *

  * @param dest target codec context, should be initialized with
  *             avcodec_alloc_context3(), but otherwise uninitialized
  * @param src source codec context
  * @return AVERROR() on error (e.g. memory allocation error), 0 on success

  */

 int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src);

 
 /**

  * Allocate an AVFrame and set its fields to default values.  The resulting

  * struct must be freed using avcodec_free_frame().

  *

  * @return An AVFrame filled with default values or NULL on failure.
  * @see avcodec_get_frame_defaults

  */

 AVFrame *avcodec_alloc_frame(void);

 /**

  * Set the fields of the given AVFrame to default values.

  *

  * @param frame The AVFrame of which the fields should be set to default values.

  */

 void avcodec_get_frame_defaults(AVFrame *frame);

 
 /**

  * Free the frame and any dynamically allocated objects in it,
  * e.g. extended_data.
  *
  * @param frame frame to be freed. The pointer will be set to NULL.
  *
  * @warning this function does NOT free the data buffers themselves
  * (it does not know how, since they might have been allocated with
  *  a custom get_buffer()).
  */
 void avcodec_free_frame(AVFrame **frame);

 #if FF_API_AVCODEC_OPEN

 /**

  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
  * function the context has to be allocated.

  *

  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
  * retrieving a codec.

  *

  * @warning This function is not thread safe!

  *

  * @code

  * avcodec_register_all();

  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);

  * if (!codec)
  *     exit(1);
  *
  * context = avcodec_alloc_context3(codec);
  *
  * if (avcodec_open(context, codec) < 0)
  *     exit(1);

  * @endcode
  *

  * @param avctx The context which will be set up to use the given codec.
  * @param codec The codec to use within the context.
  * @return zero on success, a negative value on error
  * @see avcodec_alloc_context3, avcodec_find_decoder, avcodec_find_encoder, avcodec_close
  *
  * @deprecated use avcodec_open2

  */

 attribute_deprecated
 int avcodec_open(AVCodecContext *avctx, AVCodec *codec);
 #endif

 /**

  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
  * function the context has to be allocated with avcodec_alloc_context3().

  *

  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
  * retrieving a codec.
  *
  * @warning This function is not thread safe!

  *
  * @code

  * avcodec_register_all();
  * av_dict_set(&opts, "b", "2.5M", 0);

  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);

  * if (!codec)
  *     exit(1);
  *
  * context = avcodec_alloc_context3(codec);
  *
  * if (avcodec_open2(context, codec, opts) < 0)
  *     exit(1);

  * @endcode
  *

  * @param avctx The context to initialize.
  * @param codec The codec to open this context for. If a non-NULL codec has been
  *              previously passed to avcodec_alloc_context3() or
  *              avcodec_get_context_defaults3() for this context, then this
  *              parameter MUST be either NULL or equal to the previously passed
  *              codec.
  * @param options A dictionary filled with AVCodecContext and codec-private options.
  *                On return this object will be filled with options that were not found.
  *
  * @return zero on success, a negative value on error
  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
  *      av_dict_set(), av_opt_find().

  */

 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);

 /**
  * Close a given AVCodecContext and free all the data associated with it
  * (but not the AVCodecContext itself).
  *
  * Calling this function on an AVCodecContext that hasn't been opened will free
  * the codec-specific data allocated in avcodec_alloc_context3() /
  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
  * do nothing.
  */
 int avcodec_close(AVCodecContext *avctx);

 /**
  * Free all allocated data in the given subtitle struct.
  *
  * @param sub AVSubtitle to free.
  */
 void avsubtitle_free(AVSubtitle *sub);

 /**

  * @}

  */

 /**

  * @addtogroup lavc_packet
  * @{

  */
 

 /**

  * Default packet destructor.

  */

 void av_destruct_packet(AVPacket *pkt);

 /**

  * Initialize optional fields of a packet with default values.

  *

  * Note, this does not touch the data and size members, which have to be
  * initialized separately.
  *

  * @param pkt packet

  */

 void av_init_packet(AVPacket *pkt);

 
 /**

  * Allocate the payload of a packet and initialize its fields with
  * default values.

  *

  * @param pkt packet
  * @param size wanted payload size
  * @return 0 if OK, AVERROR_xxx otherwise

  */

 int av_new_packet(AVPacket *pkt, int size);

 
 /**

  * Reduce packet size, correctly zeroing padding

  *

  * @param pkt packet
  * @param size new size

  */

 void av_shrink_packet(AVPacket *pkt, int size);

 
 /**

  * Increase packet size, correctly zeroing padding

  *

  * @param pkt packet
  * @param grow_by number of bytes by which to increase the size of the packet

  */

 int av_grow_packet(AVPacket *pkt, int grow_by);

 
 /**

  * @warning This is a hack - the packet memory allocation stuff is broken. The
  * packet is allocated if it was not really allocated.

  */

 int av_dup_packet(AVPacket *pkt);

 /**

  * Copy packet, including contents
  *
  * @return 0 on success, negative AVERROR on fail
  */
 int av_copy_packet(AVPacket *dst, AVPacket *src);
 
 /**

  * Free a packet.

  *

  * @param pkt packet to free

  */

 void av_free_packet(AVPacket *pkt);

 
 /**

  * Allocate new information of a packet.

  *

  * @param pkt packet
  * @param type side information type
  * @param size side information size
  * @return pointer to fresh allocated data or NULL otherwise

  */

 uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
                                  int size);

 /**

  * Shrink the already allocated side data buffer

  *

  * @param pkt packet
  * @param type side information type
  * @param size new side information size
  * @return 0 on success, < 0 on failure

  */

 int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
                                int size);

 /**

  * Get side information from packet.

  *

  * @param pkt packet
  * @param type desired side information type
  * @param size pointer for side information size to store (optional)
  * @return pointer to data if present or NULL otherwise

  */

 uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
                                  int *size);
 

 int av_packet_merge_side_data(AVPacket *pkt);
 
 int av_packet_split_side_data(AVPacket *pkt);

 /**

  * @}

  */

 /**

  * @addtogroup lavc_decoding
  * @{

  */
 
 /**

  * Find a registered decoder with a matching codec ID.

  *

  * @param id AVCodecID of the requested decoder

  * @return A decoder if one was found, NULL otherwise.

  */

 AVCodec *avcodec_find_decoder(enum AVCodecID id);

 
 /**

  * Find a registered decoder with the specified name.

  *

  * @param name name of the requested decoder
  * @return A decoder if one was found, NULL otherwise.

  */

 AVCodec *avcodec_find_decoder_by_name(const char *name);

 int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic);
 void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic);

 int avcodec_default_reget_buffer(AVCodecContext *s, AVFrame *pic);

 
 /**

  * Return the amount of padding in pixels which the get_buffer callback must

  * provide around the edge of the image for codecs which do not have the
  * CODEC_FLAG_EMU_EDGE flag.
  *
  * @return Required padding in pixels.
  */
 unsigned avcodec_get_edge_width(void);

 /**

  * Modify width and height values so that they will result in a memory

  * buffer that is acceptable for the codec if you do not use any horizontal
  * padding.

  *
  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
  * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
  * according to avcodec_get_edge_width() before.

  */

 void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);

 /**

  * Modify width and height values so that they will result in a memory

  * buffer that is acceptable for the codec if you also ensure that all
  * line sizes are a multiple of the respective linesize_align[i].

  *
  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
  * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
  * according to avcodec_get_edge_width() before.

  */
 void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,

                                int linesize_align[AV_NUM_DATA_POINTERS]);

 #if FF_API_OLD_DECODE_AUDIO

 /**

  * Wrapper function which calls avcodec_decode_audio4.
  *
  * @deprecated Use avcodec_decode_audio4 instead.
  *

  * Decode the audio frame of size avpkt->size from avpkt->data into samples.

  * Some decoders may support multiple frames in a single AVPacket, such

  * decoders would then just decode the first frame. In this case,
  * avcodec_decode_audio3 has to be called again with an AVPacket that contains
  * the remaining data in order to decode the second frame etc.

  * If no frame

  * could be outputted, frame_size_ptr is zero. Otherwise, it is the

  * decompressed frame size in bytes.

  *

  * @warning You must set frame_size_ptr to the allocated size of the

  * output buffer before calling avcodec_decode_audio3().

  *

  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than

  * the actual read bytes because some optimized bitstream readers read 32 or 64
  * bits at once and could read over the end.
  *

  * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that

  * no overreading happens for damaged MPEG streams.

  *

  * @warning You must not provide a custom get_buffer() when using
  * avcodec_decode_audio3().  Doing so will override it with
  * avcodec_default_get_buffer.  Use avcodec_decode_audio4() instead,
  * which does allow the application to provide a custom get_buffer().
  *

  * @note You might have to align the input buffer avpkt->data and output buffer

  * samples. The alignment requirements depend on the CPU: On some CPUs it isn't